zig/lib/std/hash_map.zig
mlugg f26dda2117 all: migrate code to new cast builtin syntax
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:

* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
2023-06-24 16:56:39 -07:00

2221 lines
86 KiB
Zig

const std = @import("std.zig");
const builtin = @import("builtin");
const assert = debug.assert;
const autoHash = std.hash.autoHash;
const debug = std.debug;
const math = std.math;
const mem = std.mem;
const meta = std.meta;
const trait = meta.trait;
const Allocator = mem.Allocator;
const Wyhash = std.hash.Wyhash;
pub fn getAutoHashFn(comptime K: type, comptime Context: type) (fn (Context, K) u64) {
comptime {
assert(@hasDecl(std, "StringHashMap")); // detect when the following message needs updated
if (K == []const u8) {
@compileError("std.auto_hash.autoHash does not allow slices here (" ++
@typeName(K) ++
") because the intent is unclear. " ++
"Consider using std.StringHashMap for hashing the contents of []const u8. " ++
"Alternatively, consider using std.auto_hash.hash or providing your own hash function instead.");
}
}
return struct {
fn hash(ctx: Context, key: K) u64 {
_ = ctx;
if (comptime trait.hasUniqueRepresentation(K)) {
return Wyhash.hash(0, std.mem.asBytes(&key));
} else {
var hasher = Wyhash.init(0);
autoHash(&hasher, key);
return hasher.final();
}
}
}.hash;
}
pub fn getAutoEqlFn(comptime K: type, comptime Context: type) (fn (Context, K, K) bool) {
return struct {
fn eql(ctx: Context, a: K, b: K) bool {
_ = ctx;
return meta.eql(a, b);
}
}.eql;
}
pub fn AutoHashMap(comptime K: type, comptime V: type) type {
return HashMap(K, V, AutoContext(K), default_max_load_percentage);
}
pub fn AutoHashMapUnmanaged(comptime K: type, comptime V: type) type {
return HashMapUnmanaged(K, V, AutoContext(K), default_max_load_percentage);
}
pub fn AutoContext(comptime K: type) type {
return struct {
pub const hash = getAutoHashFn(K, @This());
pub const eql = getAutoEqlFn(K, @This());
};
}
/// Builtin hashmap for strings as keys.
/// Key memory is managed by the caller. Keys and values
/// will not automatically be freed.
pub fn StringHashMap(comptime V: type) type {
return HashMap([]const u8, V, StringContext, default_max_load_percentage);
}
/// Key memory is managed by the caller. Keys and values
/// will not automatically be freed.
pub fn StringHashMapUnmanaged(comptime V: type) type {
return HashMapUnmanaged([]const u8, V, StringContext, default_max_load_percentage);
}
pub const StringContext = struct {
pub fn hash(self: @This(), s: []const u8) u64 {
_ = self;
return hashString(s);
}
pub fn eql(self: @This(), a: []const u8, b: []const u8) bool {
_ = self;
return eqlString(a, b);
}
};
pub fn eqlString(a: []const u8, b: []const u8) bool {
return mem.eql(u8, a, b);
}
pub fn hashString(s: []const u8) u64 {
return std.hash.Wyhash.hash(0, s);
}
pub const StringIndexContext = struct {
bytes: *std.ArrayListUnmanaged(u8),
pub fn eql(self: @This(), a: u32, b: u32) bool {
_ = self;
return a == b;
}
pub fn hash(self: @This(), x: u32) u64 {
const x_slice = mem.sliceTo(@as([*:0]const u8, @ptrCast(self.bytes.items.ptr)) + x, 0);
return hashString(x_slice);
}
};
pub const StringIndexAdapter = struct {
bytes: *std.ArrayListUnmanaged(u8),
pub fn eql(self: @This(), a_slice: []const u8, b: u32) bool {
const b_slice = mem.sliceTo(@as([*:0]const u8, @ptrCast(self.bytes.items.ptr)) + b, 0);
return mem.eql(u8, a_slice, b_slice);
}
pub fn hash(self: @This(), adapted_key: []const u8) u64 {
_ = self;
return hashString(adapted_key);
}
};
pub const default_max_load_percentage = 80;
/// This function issues a compile error with a helpful message if there
/// is a problem with the provided context type. A context must have the following
/// member functions:
/// - hash(self, PseudoKey) Hash
/// - eql(self, PseudoKey, Key) bool
/// If you are passing a context to a *Adapted function, PseudoKey is the type
/// of the key parameter. Otherwise, when creating a HashMap or HashMapUnmanaged
/// type, PseudoKey = Key = K.
pub fn verifyContext(
comptime RawContext: type,
comptime PseudoKey: type,
comptime Key: type,
comptime Hash: type,
comptime is_array: bool,
) void {
comptime {
var allow_const_ptr = false;
var allow_mutable_ptr = false;
// Context is the actual namespace type. RawContext may be a pointer to Context.
var Context = RawContext;
// Make sure the context is a namespace type which may have member functions
switch (@typeInfo(Context)) {
.Struct, .Union, .Enum => {},
// Special-case .Opaque for a better error message
.Opaque => @compileError("Hash context must be a type with hash and eql member functions. Cannot use " ++ @typeName(Context) ++ " because it is opaque. Use a pointer instead."),
.Pointer => |ptr| {
if (ptr.size != .One) {
@compileError("Hash context must be a type with hash and eql member functions. Cannot use " ++ @typeName(Context) ++ " because it is not a single pointer.");
}
Context = ptr.child;
allow_const_ptr = true;
allow_mutable_ptr = !ptr.is_const;
switch (@typeInfo(Context)) {
.Struct, .Union, .Enum, .Opaque => {},
else => @compileError("Hash context must be a type with hash and eql member functions. Cannot use " ++ @typeName(Context)),
}
},
else => @compileError("Hash context must be a type with hash and eql member functions. Cannot use " ++ @typeName(Context)),
}
// Keep track of multiple errors so we can report them all.
var errors: []const u8 = "";
// Put common errors here, they will only be evaluated
// if the error is actually triggered.
const lazy = struct {
const prefix = "\n ";
const deep_prefix = prefix ++ " ";
const hash_signature = "fn (self, " ++ @typeName(PseudoKey) ++ ") " ++ @typeName(Hash);
const index_param = if (is_array) ", b_index: usize" else "";
const eql_signature = "fn (self, " ++ @typeName(PseudoKey) ++ ", " ++
@typeName(Key) ++ index_param ++ ") bool";
const err_invalid_hash_signature = prefix ++ @typeName(Context) ++ ".hash must be " ++ hash_signature ++
deep_prefix ++ "but is actually " ++ @typeName(@TypeOf(Context.hash));
const err_invalid_eql_signature = prefix ++ @typeName(Context) ++ ".eql must be " ++ eql_signature ++
deep_prefix ++ "but is actually " ++ @typeName(@TypeOf(Context.eql));
};
// Verify Context.hash(self, PseudoKey) => Hash
if (@hasDecl(Context, "hash")) {
const hash = Context.hash;
const info = @typeInfo(@TypeOf(hash));
if (info == .Fn) {
const func = info.Fn;
if (func.params.len != 2) {
errors = errors ++ lazy.err_invalid_hash_signature;
} else {
var emitted_signature = false;
if (func.params[0].type) |Self| {
if (Self == Context) {
// pass, this is always fine.
} else if (Self == *const Context) {
if (!allow_const_ptr) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_hash_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context) ++ ", but is " ++ @typeName(Self);
errors = errors ++ lazy.deep_prefix ++ "Note: Cannot be a pointer because it is passed by value.";
}
} else if (Self == *Context) {
if (!allow_mutable_ptr) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_hash_signature;
emitted_signature = true;
}
if (!allow_const_ptr) {
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context) ++ ", but is " ++ @typeName(Self);
errors = errors ++ lazy.deep_prefix ++ "Note: Cannot be a pointer because it is passed by value.";
} else {
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context) ++ " or " ++ @typeName(*const Context) ++ ", but is " ++ @typeName(Self);
errors = errors ++ lazy.deep_prefix ++ "Note: Cannot be non-const because it is passed by const pointer.";
}
}
} else {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_hash_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context);
if (allow_const_ptr) {
errors = errors ++ " or " ++ @typeName(*const Context);
if (allow_mutable_ptr) {
errors = errors ++ " or " ++ @typeName(*Context);
}
}
errors = errors ++ ", but is " ++ @typeName(Self);
}
}
if (func.params[1].type != null and func.params[1].type.? != PseudoKey) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_hash_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "Second parameter must be " ++ @typeName(PseudoKey) ++ ", but is " ++ @typeName(func.params[1].type.?);
}
if (func.return_type != null and func.return_type.? != Hash) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_hash_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "Return type must be " ++ @typeName(Hash) ++ ", but was " ++ @typeName(func.return_type.?);
}
// If any of these are generic (null), we cannot verify them.
// The call sites check the return type, but cannot check the
// parameters. This may cause compile errors with generic hash/eql functions.
}
} else {
errors = errors ++ lazy.err_invalid_hash_signature;
}
} else {
errors = errors ++ lazy.prefix ++ @typeName(Context) ++ " must declare a hash function with signature " ++ lazy.hash_signature;
}
// Verify Context.eql(self, PseudoKey, Key) => bool
if (@hasDecl(Context, "eql")) {
const eql = Context.eql;
const info = @typeInfo(@TypeOf(eql));
if (info == .Fn) {
const func = info.Fn;
const args_len = if (is_array) 4 else 3;
if (func.params.len != args_len) {
errors = errors ++ lazy.err_invalid_eql_signature;
} else {
var emitted_signature = false;
if (func.params[0].type) |Self| {
if (Self == Context) {
// pass, this is always fine.
} else if (Self == *const Context) {
if (!allow_const_ptr) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_eql_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context) ++ ", but is " ++ @typeName(Self);
errors = errors ++ lazy.deep_prefix ++ "Note: Cannot be a pointer because it is passed by value.";
}
} else if (Self == *Context) {
if (!allow_mutable_ptr) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_eql_signature;
emitted_signature = true;
}
if (!allow_const_ptr) {
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context) ++ ", but is " ++ @typeName(Self);
errors = errors ++ lazy.deep_prefix ++ "Note: Cannot be a pointer because it is passed by value.";
} else {
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context) ++ " or " ++ @typeName(*const Context) ++ ", but is " ++ @typeName(Self);
errors = errors ++ lazy.deep_prefix ++ "Note: Cannot be non-const because it is passed by const pointer.";
}
}
} else {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_eql_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "First parameter must be " ++ @typeName(Context);
if (allow_const_ptr) {
errors = errors ++ " or " ++ @typeName(*const Context);
if (allow_mutable_ptr) {
errors = errors ++ " or " ++ @typeName(*Context);
}
}
errors = errors ++ ", but is " ++ @typeName(Self);
}
}
if (func.params[1].type.? != PseudoKey) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_eql_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "Second parameter must be " ++ @typeName(PseudoKey) ++ ", but is " ++ @typeName(func.params[1].type.?);
}
if (func.params[2].type.? != Key) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_eql_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "Third parameter must be " ++ @typeName(Key) ++ ", but is " ++ @typeName(func.params[2].type.?);
}
if (func.return_type.? != bool) {
if (!emitted_signature) {
errors = errors ++ lazy.err_invalid_eql_signature;
emitted_signature = true;
}
errors = errors ++ lazy.deep_prefix ++ "Return type must be bool, but was " ++ @typeName(func.return_type.?);
}
// If any of these are generic (null), we cannot verify them.
// The call sites check the return type, but cannot check the
// parameters. This may cause compile errors with generic hash/eql functions.
}
} else {
errors = errors ++ lazy.err_invalid_eql_signature;
}
} else {
errors = errors ++ lazy.prefix ++ @typeName(Context) ++ " must declare a eql function with signature " ++ lazy.eql_signature;
}
if (errors.len != 0) {
// errors begins with a newline (from lazy.prefix)
@compileError("Problems found with hash context type " ++ @typeName(Context) ++ ":" ++ errors);
}
}
}
/// General purpose hash table.
/// No order is guaranteed and any modification invalidates live iterators.
/// It provides fast operations (lookup, insertion, deletion) with quite high
/// load factors (up to 80% by default) for low memory usage.
/// For a hash map that can be initialized directly that does not store an Allocator
/// field, see `HashMapUnmanaged`.
/// If iterating over the table entries is a strong usecase and needs to be fast,
/// prefer the alternative `std.ArrayHashMap`.
/// Context must be a struct type with two member functions:
/// hash(self, K) u64
/// eql(self, K, K) bool
/// Adapted variants of many functions are provided. These variants
/// take a pseudo key instead of a key. Their context must have the functions:
/// hash(self, PseudoKey) u64
/// eql(self, PseudoKey, K) bool
pub fn HashMap(
comptime K: type,
comptime V: type,
comptime Context: type,
comptime max_load_percentage: u64,
) type {
return struct {
unmanaged: Unmanaged,
allocator: Allocator,
ctx: Context,
comptime {
verifyContext(Context, K, K, u64, false);
}
/// The type of the unmanaged hash map underlying this wrapper
pub const Unmanaged = HashMapUnmanaged(K, V, Context, max_load_percentage);
/// An entry, containing pointers to a key and value stored in the map
pub const Entry = Unmanaged.Entry;
/// A copy of a key and value which are no longer in the map
pub const KV = Unmanaged.KV;
/// The integer type that is the result of hashing
pub const Hash = Unmanaged.Hash;
/// The iterator type returned by iterator()
pub const Iterator = Unmanaged.Iterator;
pub const KeyIterator = Unmanaged.KeyIterator;
pub const ValueIterator = Unmanaged.ValueIterator;
/// The integer type used to store the size of the map
pub const Size = Unmanaged.Size;
/// The type returned from getOrPut and variants
pub const GetOrPutResult = Unmanaged.GetOrPutResult;
const Self = @This();
/// Create a managed hash map with an empty context.
/// If the context is not zero-sized, you must use
/// initContext(allocator, ctx) instead.
pub fn init(allocator: Allocator) Self {
if (@sizeOf(Context) != 0) {
@compileError("Context must be specified! Call initContext(allocator, ctx) instead.");
}
return .{
.unmanaged = .{},
.allocator = allocator,
.ctx = undefined, // ctx is zero-sized so this is safe.
};
}
/// Create a managed hash map with a context
pub fn initContext(allocator: Allocator, ctx: Context) Self {
return .{
.unmanaged = .{},
.allocator = allocator,
.ctx = ctx,
};
}
/// Release the backing array and invalidate this map.
/// This does *not* deinit keys, values, or the context!
/// If your keys or values need to be released, ensure
/// that that is done before calling this function.
pub fn deinit(self: *Self) void {
self.unmanaged.deinit(self.allocator);
self.* = undefined;
}
/// Empty the map, but keep the backing allocation for future use.
/// This does *not* free keys or values! Be sure to
/// release them if they need deinitialization before
/// calling this function.
pub fn clearRetainingCapacity(self: *Self) void {
return self.unmanaged.clearRetainingCapacity();
}
/// Empty the map and release the backing allocation.
/// This does *not* free keys or values! Be sure to
/// release them if they need deinitialization before
/// calling this function.
pub fn clearAndFree(self: *Self) void {
return self.unmanaged.clearAndFree(self.allocator);
}
/// Return the number of items in the map.
pub fn count(self: Self) Size {
return self.unmanaged.count();
}
/// Create an iterator over the entries in the map.
/// The iterator is invalidated if the map is modified.
pub fn iterator(self: *const Self) Iterator {
return self.unmanaged.iterator();
}
/// Create an iterator over the keys in the map.
/// The iterator is invalidated if the map is modified.
pub fn keyIterator(self: *const Self) KeyIterator {
return self.unmanaged.keyIterator();
}
/// Create an iterator over the values in the map.
/// The iterator is invalidated if the map is modified.
pub fn valueIterator(self: *const Self) ValueIterator {
return self.unmanaged.valueIterator();
}
/// If key exists this function cannot fail.
/// If there is an existing item with `key`, then the result
/// `Entry` pointers point to it, and found_existing is true.
/// Otherwise, puts a new item with undefined value, and
/// the `Entry` pointers point to it. Caller should then initialize
/// the value (but not the key).
pub fn getOrPut(self: *Self, key: K) Allocator.Error!GetOrPutResult {
return self.unmanaged.getOrPutContext(self.allocator, key, self.ctx);
}
/// If key exists this function cannot fail.
/// If there is an existing item with `key`, then the result
/// `Entry` pointers point to it, and found_existing is true.
/// Otherwise, puts a new item with undefined key and value, and
/// the `Entry` pointers point to it. Caller must then initialize
/// the key and value.
pub fn getOrPutAdapted(self: *Self, key: anytype, ctx: anytype) Allocator.Error!GetOrPutResult {
return self.unmanaged.getOrPutContextAdapted(self.allocator, key, ctx, self.ctx);
}
/// If there is an existing item with `key`, then the result
/// `Entry` pointers point to it, and found_existing is true.
/// Otherwise, puts a new item with undefined value, and
/// the `Entry` pointers point to it. Caller should then initialize
/// the value (but not the key).
/// If a new entry needs to be stored, this function asserts there
/// is enough capacity to store it.
pub fn getOrPutAssumeCapacity(self: *Self, key: K) GetOrPutResult {
return self.unmanaged.getOrPutAssumeCapacityContext(key, self.ctx);
}
/// If there is an existing item with `key`, then the result
/// `Entry` pointers point to it, and found_existing is true.
/// Otherwise, puts a new item with undefined value, and
/// the `Entry` pointers point to it. Caller must then initialize
/// the key and value.
/// If a new entry needs to be stored, this function asserts there
/// is enough capacity to store it.
pub fn getOrPutAssumeCapacityAdapted(self: *Self, key: anytype, ctx: anytype) GetOrPutResult {
return self.unmanaged.getOrPutAssumeCapacityAdapted(key, ctx);
}
pub fn getOrPutValue(self: *Self, key: K, value: V) Allocator.Error!Entry {
return self.unmanaged.getOrPutValueContext(self.allocator, key, value, self.ctx);
}
/// Increases capacity, guaranteeing that insertions up until the
/// `expected_count` will not cause an allocation, and therefore cannot fail.
pub fn ensureTotalCapacity(self: *Self, expected_count: Size) Allocator.Error!void {
return self.unmanaged.ensureTotalCapacityContext(self.allocator, expected_count, self.ctx);
}
/// Increases capacity, guaranteeing that insertions up until
/// `additional_count` **more** items will not cause an allocation, and
/// therefore cannot fail.
pub fn ensureUnusedCapacity(self: *Self, additional_count: Size) Allocator.Error!void {
return self.unmanaged.ensureUnusedCapacityContext(self.allocator, additional_count, self.ctx);
}
/// Returns the number of total elements which may be present before it is
/// no longer guaranteed that no allocations will be performed.
pub fn capacity(self: *Self) Size {
return self.unmanaged.capacity();
}
/// Clobbers any existing data. To detect if a put would clobber
/// existing data, see `getOrPut`.
pub fn put(self: *Self, key: K, value: V) Allocator.Error!void {
return self.unmanaged.putContext(self.allocator, key, value, self.ctx);
}
/// Inserts a key-value pair into the hash map, asserting that no previous
/// entry with the same key is already present
pub fn putNoClobber(self: *Self, key: K, value: V) Allocator.Error!void {
return self.unmanaged.putNoClobberContext(self.allocator, key, value, self.ctx);
}
/// Asserts there is enough capacity to store the new key-value pair.
/// Clobbers any existing data. To detect if a put would clobber
/// existing data, see `getOrPutAssumeCapacity`.
pub fn putAssumeCapacity(self: *Self, key: K, value: V) void {
return self.unmanaged.putAssumeCapacityContext(key, value, self.ctx);
}
/// Asserts there is enough capacity to store the new key-value pair.
/// Asserts that it does not clobber any existing data.
/// To detect if a put would clobber existing data, see `getOrPutAssumeCapacity`.
pub fn putAssumeCapacityNoClobber(self: *Self, key: K, value: V) void {
return self.unmanaged.putAssumeCapacityNoClobberContext(key, value, self.ctx);
}
/// Inserts a new `Entry` into the hash map, returning the previous one, if any.
pub fn fetchPut(self: *Self, key: K, value: V) Allocator.Error!?KV {
return self.unmanaged.fetchPutContext(self.allocator, key, value, self.ctx);
}
/// Inserts a new `Entry` into the hash map, returning the previous one, if any.
/// If insertion happuns, asserts there is enough capacity without allocating.
pub fn fetchPutAssumeCapacity(self: *Self, key: K, value: V) ?KV {
return self.unmanaged.fetchPutAssumeCapacityContext(key, value, self.ctx);
}
/// Removes a value from the map and returns the removed kv pair.
pub fn fetchRemove(self: *Self, key: K) ?KV {
return self.unmanaged.fetchRemoveContext(key, self.ctx);
}
pub fn fetchRemoveAdapted(self: *Self, key: anytype, ctx: anytype) ?KV {
return self.unmanaged.fetchRemoveAdapted(key, ctx);
}
/// Finds the value associated with a key in the map
pub fn get(self: Self, key: K) ?V {
return self.unmanaged.getContext(key, self.ctx);
}
pub fn getAdapted(self: Self, key: anytype, ctx: anytype) ?V {
return self.unmanaged.getAdapted(key, ctx);
}
pub fn getPtr(self: Self, key: K) ?*V {
return self.unmanaged.getPtrContext(key, self.ctx);
}
pub fn getPtrAdapted(self: Self, key: anytype, ctx: anytype) ?*V {
return self.unmanaged.getPtrAdapted(key, ctx);
}
/// Finds the actual key associated with an adapted key in the map
pub fn getKey(self: Self, key: K) ?K {
return self.unmanaged.getKeyContext(key, self.ctx);
}
pub fn getKeyAdapted(self: Self, key: anytype, ctx: anytype) ?K {
return self.unmanaged.getKeyAdapted(key, ctx);
}
pub fn getKeyPtr(self: Self, key: K) ?*K {
return self.unmanaged.getKeyPtrContext(key, self.ctx);
}
pub fn getKeyPtrAdapted(self: Self, key: anytype, ctx: anytype) ?*K {
return self.unmanaged.getKeyPtrAdapted(key, ctx);
}
/// Finds the key and value associated with a key in the map
pub fn getEntry(self: Self, key: K) ?Entry {
return self.unmanaged.getEntryContext(key, self.ctx);
}
pub fn getEntryAdapted(self: Self, key: anytype, ctx: anytype) ?Entry {
return self.unmanaged.getEntryAdapted(key, ctx);
}
/// Check if the map contains a key
pub fn contains(self: Self, key: K) bool {
return self.unmanaged.containsContext(key, self.ctx);
}
pub fn containsAdapted(self: Self, key: anytype, ctx: anytype) bool {
return self.unmanaged.containsAdapted(key, ctx);
}
/// If there is an `Entry` with a matching key, it is deleted from
/// the hash map, and this function returns true. Otherwise this
/// function returns false.
pub fn remove(self: *Self, key: K) bool {
return self.unmanaged.removeContext(key, self.ctx);
}
pub fn removeAdapted(self: *Self, key: anytype, ctx: anytype) bool {
return self.unmanaged.removeAdapted(key, ctx);
}
/// Delete the entry with key pointed to by keyPtr from the hash map.
/// keyPtr is assumed to be a valid pointer to a key that is present
/// in the hash map.
pub fn removeByPtr(self: *Self, keyPtr: *K) void {
self.unmanaged.removeByPtr(keyPtr);
}
/// Creates a copy of this map, using the same allocator
pub fn clone(self: Self) Allocator.Error!Self {
var other = try self.unmanaged.cloneContext(self.allocator, self.ctx);
return other.promoteContext(self.allocator, self.ctx);
}
/// Creates a copy of this map, using a specified allocator
pub fn cloneWithAllocator(self: Self, new_allocator: Allocator) Allocator.Error!Self {
var other = try self.unmanaged.cloneContext(new_allocator, self.ctx);
return other.promoteContext(new_allocator, self.ctx);
}
/// Creates a copy of this map, using a specified context
pub fn cloneWithContext(self: Self, new_ctx: anytype) Allocator.Error!HashMap(K, V, @TypeOf(new_ctx), max_load_percentage) {
var other = try self.unmanaged.cloneContext(self.allocator, new_ctx);
return other.promoteContext(self.allocator, new_ctx);
}
/// Creates a copy of this map, using a specified allocator and context.
pub fn cloneWithAllocatorAndContext(
self: Self,
new_allocator: Allocator,
new_ctx: anytype,
) Allocator.Error!HashMap(K, V, @TypeOf(new_ctx), max_load_percentage) {
var other = try self.unmanaged.cloneContext(new_allocator, new_ctx);
return other.promoteContext(new_allocator, new_ctx);
}
/// Set the map to an empty state, making deinitialization a no-op, and
/// returning a copy of the original.
pub fn move(self: *Self) Self {
const result = self.*;
self.unmanaged = .{};
return result;
}
};
}
/// A HashMap based on open addressing and linear probing.
/// A lookup or modification typically occurs only 2 cache misses.
/// No order is guaranteed and any modification invalidates live iterators.
/// It achieves good performance with quite high load factors (by default,
/// grow is triggered at 80% full) and only one byte of overhead per element.
/// The struct itself is only 16 bytes for a small footprint. This comes at
/// the price of handling size with u32, which should be reasonable enough
/// for almost all uses.
/// Deletions are achieved with tombstones.
pub fn HashMapUnmanaged(
comptime K: type,
comptime V: type,
comptime Context: type,
comptime max_load_percentage: u64,
) type {
if (max_load_percentage <= 0 or max_load_percentage >= 100)
@compileError("max_load_percentage must be between 0 and 100.");
return struct {
const Self = @This();
comptime {
verifyContext(Context, K, K, u64, false);
}
// This is actually a midway pointer to the single buffer containing
// a `Header` field, the `Metadata`s and `Entry`s.
// At `-@sizeOf(Header)` is the Header field.
// At `sizeOf(Metadata) * capacity + offset`, which is pointed to by
// self.header().entries, is the array of entries.
// This means that the hashmap only holds one live allocation, to
// reduce memory fragmentation and struct size.
/// Pointer to the metadata.
metadata: ?[*]Metadata = null,
/// Current number of elements in the hashmap.
size: Size = 0,
// Having a countdown to grow reduces the number of instructions to
// execute when determining if the hashmap has enough capacity already.
/// Number of available slots before a grow is needed to satisfy the
/// `max_load_percentage`.
available: Size = 0,
// This is purely empirical and not a /very smart magic constant™/.
/// Capacity of the first grow when bootstrapping the hashmap.
const minimal_capacity = 8;
// This hashmap is specially designed for sizes that fit in a u32.
pub const Size = u32;
// u64 hashes guarantee us that the fingerprint bits will never be used
// to compute the index of a slot, maximizing the use of entropy.
pub const Hash = u64;
pub const Entry = struct {
key_ptr: *K,
value_ptr: *V,
};
pub const KV = struct {
key: K,
value: V,
};
const Header = struct {
values: [*]V,
keys: [*]K,
capacity: Size,
};
/// Metadata for a slot. It can be in three states: empty, used or
/// tombstone. Tombstones indicate that an entry was previously used,
/// they are a simple way to handle removal.
/// To this state, we add 7 bits from the slot's key hash. These are
/// used as a fast way to disambiguate between entries without
/// having to use the equality function. If two fingerprints are
/// different, we know that we don't have to compare the keys at all.
/// The 7 bits are the highest ones from a 64 bit hash. This way, not
/// only we use the `log2(capacity)` lowest bits from the hash to determine
/// a slot index, but we use 7 more bits to quickly resolve collisions
/// when multiple elements with different hashes end up wanting to be in the same slot.
/// Not using the equality function means we don't have to read into
/// the entries array, likely avoiding a cache miss and a potentially
/// costly function call.
const Metadata = packed struct {
const FingerPrint = u7;
const free: FingerPrint = 0;
const tombstone: FingerPrint = 1;
fingerprint: FingerPrint = free,
used: u1 = 0,
const slot_free = @as(u8, @bitCast(Metadata{ .fingerprint = free }));
const slot_tombstone = @as(u8, @bitCast(Metadata{ .fingerprint = tombstone }));
pub fn isUsed(self: Metadata) bool {
return self.used == 1;
}
pub fn isTombstone(self: Metadata) bool {
return @as(u8, @bitCast(self)) == slot_tombstone;
}
pub fn isFree(self: Metadata) bool {
return @as(u8, @bitCast(self)) == slot_free;
}
pub fn takeFingerprint(hash: Hash) FingerPrint {
const hash_bits = @typeInfo(Hash).Int.bits;
const fp_bits = @typeInfo(FingerPrint).Int.bits;
return @as(FingerPrint, @truncate(hash >> (hash_bits - fp_bits)));
}
pub fn fill(self: *Metadata, fp: FingerPrint) void {
self.used = 1;
self.fingerprint = fp;
}
pub fn remove(self: *Metadata) void {
self.used = 0;
self.fingerprint = tombstone;
}
};
comptime {
assert(@sizeOf(Metadata) == 1);
assert(@alignOf(Metadata) == 1);
}
pub const Iterator = struct {
hm: *const Self,
index: Size = 0,
pub fn next(it: *Iterator) ?Entry {
assert(it.index <= it.hm.capacity());
if (it.hm.size == 0) return null;
const cap = it.hm.capacity();
const end = it.hm.metadata.? + cap;
var metadata = it.hm.metadata.? + it.index;
while (metadata != end) : ({
metadata += 1;
it.index += 1;
}) {
if (metadata[0].isUsed()) {
const key = &it.hm.keys()[it.index];
const value = &it.hm.values()[it.index];
it.index += 1;
return Entry{ .key_ptr = key, .value_ptr = value };
}
}
return null;
}
};
pub const KeyIterator = FieldIterator(K);
pub const ValueIterator = FieldIterator(V);
fn FieldIterator(comptime T: type) type {
return struct {
len: usize,
metadata: [*]const Metadata,
items: [*]T,
pub fn next(self: *@This()) ?*T {
while (self.len > 0) {
self.len -= 1;
const used = self.metadata[0].isUsed();
const item = &self.items[0];
self.metadata += 1;
self.items += 1;
if (used) {
return item;
}
}
return null;
}
};
}
pub const GetOrPutResult = struct {
key_ptr: *K,
value_ptr: *V,
found_existing: bool,
};
pub const Managed = HashMap(K, V, Context, max_load_percentage);
pub fn promote(self: Self, allocator: Allocator) Managed {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call promoteContext instead.");
return promoteContext(self, allocator, undefined);
}
pub fn promoteContext(self: Self, allocator: Allocator, ctx: Context) Managed {
return .{
.unmanaged = self,
.allocator = allocator,
.ctx = ctx,
};
}
fn isUnderMaxLoadPercentage(size: Size, cap: Size) bool {
return size * 100 < max_load_percentage * cap;
}
pub fn deinit(self: *Self, allocator: Allocator) void {
self.deallocate(allocator);
self.* = undefined;
}
fn capacityForSize(size: Size) Size {
var new_cap = @as(u32, @truncate((@as(u64, size) * 100) / max_load_percentage + 1));
new_cap = math.ceilPowerOfTwo(u32, new_cap) catch unreachable;
return new_cap;
}
pub fn ensureTotalCapacity(self: *Self, allocator: Allocator, new_size: Size) Allocator.Error!void {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call ensureTotalCapacityContext instead.");
return ensureTotalCapacityContext(self, allocator, new_size, undefined);
}
pub fn ensureTotalCapacityContext(self: *Self, allocator: Allocator, new_size: Size, ctx: Context) Allocator.Error!void {
if (new_size > self.size)
try self.growIfNeeded(allocator, new_size - self.size, ctx);
}
pub fn ensureUnusedCapacity(self: *Self, allocator: Allocator, additional_size: Size) Allocator.Error!void {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call ensureUnusedCapacityContext instead.");
return ensureUnusedCapacityContext(self, allocator, additional_size, undefined);
}
pub fn ensureUnusedCapacityContext(self: *Self, allocator: Allocator, additional_size: Size, ctx: Context) Allocator.Error!void {
return ensureTotalCapacityContext(self, allocator, self.count() + additional_size, ctx);
}
pub fn clearRetainingCapacity(self: *Self) void {
if (self.metadata) |_| {
self.initMetadatas();
self.size = 0;
self.available = @as(u32, @truncate((self.capacity() * max_load_percentage) / 100));
}
}
pub fn clearAndFree(self: *Self, allocator: Allocator) void {
self.deallocate(allocator);
self.size = 0;
self.available = 0;
}
pub fn count(self: *const Self) Size {
return self.size;
}
fn header(self: *const Self) *Header {
return @ptrCast(@as([*]Header, @ptrCast(@alignCast(self.metadata.?))) - 1);
}
fn keys(self: *const Self) [*]K {
return self.header().keys;
}
fn values(self: *const Self) [*]V {
return self.header().values;
}
pub fn capacity(self: *const Self) Size {
if (self.metadata == null) return 0;
return self.header().capacity;
}
pub fn iterator(self: *const Self) Iterator {
return .{ .hm = self };
}
pub fn keyIterator(self: *const Self) KeyIterator {
if (self.metadata) |metadata| {
return .{
.len = self.capacity(),
.metadata = metadata,
.items = self.keys(),
};
} else {
return .{
.len = 0,
.metadata = undefined,
.items = undefined,
};
}
}
pub fn valueIterator(self: *const Self) ValueIterator {
if (self.metadata) |metadata| {
return .{
.len = self.capacity(),
.metadata = metadata,
.items = self.values(),
};
} else {
return .{
.len = 0,
.metadata = undefined,
.items = undefined,
};
}
}
/// Insert an entry in the map. Assumes it is not already present.
pub fn putNoClobber(self: *Self, allocator: Allocator, key: K, value: V) Allocator.Error!void {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call putNoClobberContext instead.");
return self.putNoClobberContext(allocator, key, value, undefined);
}
pub fn putNoClobberContext(self: *Self, allocator: Allocator, key: K, value: V, ctx: Context) Allocator.Error!void {
assert(!self.containsContext(key, ctx));
try self.growIfNeeded(allocator, 1, ctx);
self.putAssumeCapacityNoClobberContext(key, value, ctx);
}
/// Asserts there is enough capacity to store the new key-value pair.
/// Clobbers any existing data. To detect if a put would clobber
/// existing data, see `getOrPutAssumeCapacity`.
pub fn putAssumeCapacity(self: *Self, key: K, value: V) void {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call putAssumeCapacityContext instead.");
return self.putAssumeCapacityContext(key, value, undefined);
}
pub fn putAssumeCapacityContext(self: *Self, key: K, value: V, ctx: Context) void {
const gop = self.getOrPutAssumeCapacityContext(key, ctx);
gop.value_ptr.* = value;
}
/// Insert an entry in the map. Assumes it is not already present,
/// and that no allocation is needed.
pub fn putAssumeCapacityNoClobber(self: *Self, key: K, value: V) void {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call putAssumeCapacityNoClobberContext instead.");
return self.putAssumeCapacityNoClobberContext(key, value, undefined);
}
pub fn putAssumeCapacityNoClobberContext(self: *Self, key: K, value: V, ctx: Context) void {
assert(!self.containsContext(key, ctx));
const hash = ctx.hash(key);
const mask = self.capacity() - 1;
var idx = @as(usize, @truncate(hash & mask));
var metadata = self.metadata.? + idx;
while (metadata[0].isUsed()) {
idx = (idx + 1) & mask;
metadata = self.metadata.? + idx;
}
assert(self.available > 0);
self.available -= 1;
const fingerprint = Metadata.takeFingerprint(hash);
metadata[0].fill(fingerprint);
self.keys()[idx] = key;
self.values()[idx] = value;
self.size += 1;
}
/// Inserts a new `Entry` into the hash map, returning the previous one, if any.
pub fn fetchPut(self: *Self, allocator: Allocator, key: K, value: V) Allocator.Error!?KV {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call fetchPutContext instead.");
return self.fetchPutContext(allocator, key, value, undefined);
}
pub fn fetchPutContext(self: *Self, allocator: Allocator, key: K, value: V, ctx: Context) Allocator.Error!?KV {
const gop = try self.getOrPutContext(allocator, key, ctx);
var result: ?KV = null;
if (gop.found_existing) {
result = KV{
.key = gop.key_ptr.*,
.value = gop.value_ptr.*,
};
}
gop.value_ptr.* = value;
return result;
}
/// Inserts a new `Entry` into the hash map, returning the previous one, if any.
/// If insertion happens, asserts there is enough capacity without allocating.
pub fn fetchPutAssumeCapacity(self: *Self, key: K, value: V) ?KV {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call fetchPutAssumeCapacityContext instead.");
return self.fetchPutAssumeCapacityContext(key, value, undefined);
}
pub fn fetchPutAssumeCapacityContext(self: *Self, key: K, value: V, ctx: Context) ?KV {
const gop = self.getOrPutAssumeCapacityContext(key, ctx);
var result: ?KV = null;
if (gop.found_existing) {
result = KV{
.key = gop.key_ptr.*,
.value = gop.value_ptr.*,
};
}
gop.value_ptr.* = value;
return result;
}
/// If there is an `Entry` with a matching key, it is deleted from
/// the hash map, and then returned from this function.
pub fn fetchRemove(self: *Self, key: K) ?KV {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call fetchRemoveContext instead.");
return self.fetchRemoveContext(key, undefined);
}
pub fn fetchRemoveContext(self: *Self, key: K, ctx: Context) ?KV {
return self.fetchRemoveAdapted(key, ctx);
}
pub fn fetchRemoveAdapted(self: *Self, key: anytype, ctx: anytype) ?KV {
if (self.getIndex(key, ctx)) |idx| {
const old_key = &self.keys()[idx];
const old_val = &self.values()[idx];
const result = KV{
.key = old_key.*,
.value = old_val.*,
};
self.metadata.?[idx].remove();
old_key.* = undefined;
old_val.* = undefined;
self.size -= 1;
self.available += 1;
return result;
}
return null;
}
/// Find the index containing the data for the given key.
/// Whether this function returns null is almost always
/// branched on after this function returns, and this function
/// returns null/not null from separate code paths. We
/// want the optimizer to remove that branch and instead directly
/// fuse the basic blocks after the branch to the basic blocks
/// from this function. To encourage that, this function is
/// marked as inline.
inline fn getIndex(self: Self, key: anytype, ctx: anytype) ?usize {
comptime verifyContext(@TypeOf(ctx), @TypeOf(key), K, Hash, false);
if (self.size == 0) {
return null;
}
// If you get a compile error on this line, it means that your generic hash
// function is invalid for these parameters.
const hash = ctx.hash(key);
// verifyContext can't verify the return type of generic hash functions,
// so we need to double-check it here.
if (@TypeOf(hash) != Hash) {
@compileError("Context " ++ @typeName(@TypeOf(ctx)) ++ " has a generic hash function that returns the wrong type! " ++ @typeName(Hash) ++ " was expected, but found " ++ @typeName(@TypeOf(hash)));
}
const mask = self.capacity() - 1;
const fingerprint = Metadata.takeFingerprint(hash);
// Don't loop indefinitely when there are no empty slots.
var limit = self.capacity();
var idx = @as(usize, @truncate(hash & mask));
var metadata = self.metadata.? + idx;
while (!metadata[0].isFree() and limit != 0) {
if (metadata[0].isUsed() and metadata[0].fingerprint == fingerprint) {
const test_key = &self.keys()[idx];
// If you get a compile error on this line, it means that your generic eql
// function is invalid for these parameters.
const eql = ctx.eql(key, test_key.*);
// verifyContext can't verify the return type of generic eql functions,
// so we need to double-check it here.
if (@TypeOf(eql) != bool) {
@compileError("Context " ++ @typeName(@TypeOf(ctx)) ++ " has a generic eql function that returns the wrong type! bool was expected, but found " ++ @typeName(@TypeOf(eql)));
}
if (eql) {
return idx;
}
}
limit -= 1;
idx = (idx + 1) & mask;
metadata = self.metadata.? + idx;
}
return null;
}
pub fn getEntry(self: Self, key: K) ?Entry {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getEntryContext instead.");
return self.getEntryContext(key, undefined);
}
pub fn getEntryContext(self: Self, key: K, ctx: Context) ?Entry {
return self.getEntryAdapted(key, ctx);
}
pub fn getEntryAdapted(self: Self, key: anytype, ctx: anytype) ?Entry {
if (self.getIndex(key, ctx)) |idx| {
return Entry{
.key_ptr = &self.keys()[idx],
.value_ptr = &self.values()[idx],
};
}
return null;
}
/// Insert an entry if the associated key is not already present, otherwise update preexisting value.
pub fn put(self: *Self, allocator: Allocator, key: K, value: V) Allocator.Error!void {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call putContext instead.");
return self.putContext(allocator, key, value, undefined);
}
pub fn putContext(self: *Self, allocator: Allocator, key: K, value: V, ctx: Context) Allocator.Error!void {
const result = try self.getOrPutContext(allocator, key, ctx);
result.value_ptr.* = value;
}
/// Get an optional pointer to the actual key associated with adapted key, if present.
pub fn getKeyPtr(self: Self, key: K) ?*K {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getKeyPtrContext instead.");
return self.getKeyPtrContext(key, undefined);
}
pub fn getKeyPtrContext(self: Self, key: K, ctx: Context) ?*K {
return self.getKeyPtrAdapted(key, ctx);
}
pub fn getKeyPtrAdapted(self: Self, key: anytype, ctx: anytype) ?*K {
if (self.getIndex(key, ctx)) |idx| {
return &self.keys()[idx];
}
return null;
}
/// Get a copy of the actual key associated with adapted key, if present.
pub fn getKey(self: Self, key: K) ?K {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getKeyContext instead.");
return self.getKeyContext(key, undefined);
}
pub fn getKeyContext(self: Self, key: K, ctx: Context) ?K {
return self.getKeyAdapted(key, ctx);
}
pub fn getKeyAdapted(self: Self, key: anytype, ctx: anytype) ?K {
if (self.getIndex(key, ctx)) |idx| {
return self.keys()[idx];
}
return null;
}
/// Get an optional pointer to the value associated with key, if present.
pub fn getPtr(self: Self, key: K) ?*V {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getPtrContext instead.");
return self.getPtrContext(key, undefined);
}
pub fn getPtrContext(self: Self, key: K, ctx: Context) ?*V {
return self.getPtrAdapted(key, ctx);
}
pub fn getPtrAdapted(self: Self, key: anytype, ctx: anytype) ?*V {
if (self.getIndex(key, ctx)) |idx| {
return &self.values()[idx];
}
return null;
}
/// Get a copy of the value associated with key, if present.
pub fn get(self: Self, key: K) ?V {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getContext instead.");
return self.getContext(key, undefined);
}
pub fn getContext(self: Self, key: K, ctx: Context) ?V {
return self.getAdapted(key, ctx);
}
pub fn getAdapted(self: Self, key: anytype, ctx: anytype) ?V {
if (self.getIndex(key, ctx)) |idx| {
return self.values()[idx];
}
return null;
}
pub fn getOrPut(self: *Self, allocator: Allocator, key: K) Allocator.Error!GetOrPutResult {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getOrPutContext instead.");
return self.getOrPutContext(allocator, key, undefined);
}
pub fn getOrPutContext(self: *Self, allocator: Allocator, key: K, ctx: Context) Allocator.Error!GetOrPutResult {
const gop = try self.getOrPutContextAdapted(allocator, key, ctx, ctx);
if (!gop.found_existing) {
gop.key_ptr.* = key;
}
return gop;
}
pub fn getOrPutAdapted(self: *Self, allocator: Allocator, key: anytype, key_ctx: anytype) Allocator.Error!GetOrPutResult {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getOrPutContextAdapted instead.");
return self.getOrPutContextAdapted(allocator, key, key_ctx, undefined);
}
pub fn getOrPutContextAdapted(self: *Self, allocator: Allocator, key: anytype, key_ctx: anytype, ctx: Context) Allocator.Error!GetOrPutResult {
self.growIfNeeded(allocator, 1, ctx) catch |err| {
// If allocation fails, try to do the lookup anyway.
// If we find an existing item, we can return it.
// Otherwise return the error, we could not add another.
const index = self.getIndex(key, key_ctx) orelse return err;
return GetOrPutResult{
.key_ptr = &self.keys()[index],
.value_ptr = &self.values()[index],
.found_existing = true,
};
};
return self.getOrPutAssumeCapacityAdapted(key, key_ctx);
}
pub fn getOrPutAssumeCapacity(self: *Self, key: K) GetOrPutResult {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getOrPutAssumeCapacityContext instead.");
return self.getOrPutAssumeCapacityContext(key, undefined);
}
pub fn getOrPutAssumeCapacityContext(self: *Self, key: K, ctx: Context) GetOrPutResult {
const result = self.getOrPutAssumeCapacityAdapted(key, ctx);
if (!result.found_existing) {
result.key_ptr.* = key;
}
return result;
}
pub fn getOrPutAssumeCapacityAdapted(self: *Self, key: anytype, ctx: anytype) GetOrPutResult {
comptime verifyContext(@TypeOf(ctx), @TypeOf(key), K, Hash, false);
// If you get a compile error on this line, it means that your generic hash
// function is invalid for these parameters.
const hash = ctx.hash(key);
// verifyContext can't verify the return type of generic hash functions,
// so we need to double-check it here.
if (@TypeOf(hash) != Hash) {
@compileError("Context " ++ @typeName(@TypeOf(ctx)) ++ " has a generic hash function that returns the wrong type! " ++ @typeName(Hash) ++ " was expected, but found " ++ @typeName(@TypeOf(hash)));
}
const mask = self.capacity() - 1;
const fingerprint = Metadata.takeFingerprint(hash);
var limit = self.capacity();
var idx = @as(usize, @truncate(hash & mask));
var first_tombstone_idx: usize = self.capacity(); // invalid index
var metadata = self.metadata.? + idx;
while (!metadata[0].isFree() and limit != 0) {
if (metadata[0].isUsed() and metadata[0].fingerprint == fingerprint) {
const test_key = &self.keys()[idx];
// If you get a compile error on this line, it means that your generic eql
// function is invalid for these parameters.
const eql = ctx.eql(key, test_key.*);
// verifyContext can't verify the return type of generic eql functions,
// so we need to double-check it here.
if (@TypeOf(eql) != bool) {
@compileError("Context " ++ @typeName(@TypeOf(ctx)) ++ " has a generic eql function that returns the wrong type! bool was expected, but found " ++ @typeName(@TypeOf(eql)));
}
if (eql) {
return GetOrPutResult{
.key_ptr = test_key,
.value_ptr = &self.values()[idx],
.found_existing = true,
};
}
} else if (first_tombstone_idx == self.capacity() and metadata[0].isTombstone()) {
first_tombstone_idx = idx;
}
limit -= 1;
idx = (idx + 1) & mask;
metadata = self.metadata.? + idx;
}
if (first_tombstone_idx < self.capacity()) {
// Cheap try to lower probing lengths after deletions. Recycle a tombstone.
idx = first_tombstone_idx;
metadata = self.metadata.? + idx;
}
// We're using a slot previously free or a tombstone.
self.available -= 1;
metadata[0].fill(fingerprint);
const new_key = &self.keys()[idx];
const new_value = &self.values()[idx];
new_key.* = undefined;
new_value.* = undefined;
self.size += 1;
return GetOrPutResult{
.key_ptr = new_key,
.value_ptr = new_value,
.found_existing = false,
};
}
pub fn getOrPutValue(self: *Self, allocator: Allocator, key: K, value: V) Allocator.Error!Entry {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call getOrPutValueContext instead.");
return self.getOrPutValueContext(allocator, key, value, undefined);
}
pub fn getOrPutValueContext(self: *Self, allocator: Allocator, key: K, value: V, ctx: Context) Allocator.Error!Entry {
const res = try self.getOrPutAdapted(allocator, key, ctx);
if (!res.found_existing) {
res.key_ptr.* = key;
res.value_ptr.* = value;
}
return Entry{ .key_ptr = res.key_ptr, .value_ptr = res.value_ptr };
}
/// Return true if there is a value associated with key in the map.
pub fn contains(self: *const Self, key: K) bool {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call containsContext instead.");
return self.containsContext(key, undefined);
}
pub fn containsContext(self: *const Self, key: K, ctx: Context) bool {
return self.containsAdapted(key, ctx);
}
pub fn containsAdapted(self: *const Self, key: anytype, ctx: anytype) bool {
return self.getIndex(key, ctx) != null;
}
fn removeByIndex(self: *Self, idx: usize) void {
self.metadata.?[idx].remove();
self.keys()[idx] = undefined;
self.values()[idx] = undefined;
self.size -= 1;
self.available += 1;
}
/// If there is an `Entry` with a matching key, it is deleted from
/// the hash map, and this function returns true. Otherwise this
/// function returns false.
pub fn remove(self: *Self, key: K) bool {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call removeContext instead.");
return self.removeContext(key, undefined);
}
pub fn removeContext(self: *Self, key: K, ctx: Context) bool {
return self.removeAdapted(key, ctx);
}
pub fn removeAdapted(self: *Self, key: anytype, ctx: anytype) bool {
if (self.getIndex(key, ctx)) |idx| {
self.removeByIndex(idx);
return true;
}
return false;
}
/// Delete the entry with key pointed to by keyPtr from the hash map.
/// keyPtr is assumed to be a valid pointer to a key that is present
/// in the hash map.
pub fn removeByPtr(self: *Self, keyPtr: *K) void {
// TODO: replace with pointer subtraction once supported by zig
// if @sizeOf(K) == 0 then there is at most one item in the hash
// map, which is assumed to exist as keyPtr must be valid. This
// item must be at index 0.
const idx = if (@sizeOf(K) > 0)
(@intFromPtr(keyPtr) - @intFromPtr(self.keys())) / @sizeOf(K)
else
0;
self.removeByIndex(idx);
}
fn initMetadatas(self: *Self) void {
@memset(@as([*]u8, @ptrCast(self.metadata.?))[0 .. @sizeOf(Metadata) * self.capacity()], 0);
}
// This counts the number of occupied slots (not counting tombstones), which is
// what has to stay under the max_load_percentage of capacity.
fn load(self: *const Self) Size {
const max_load = (self.capacity() * max_load_percentage) / 100;
assert(max_load >= self.available);
return @as(Size, @truncate(max_load - self.available));
}
fn growIfNeeded(self: *Self, allocator: Allocator, new_count: Size, ctx: Context) Allocator.Error!void {
if (new_count > self.available) {
try self.grow(allocator, capacityForSize(self.load() + new_count), ctx);
}
}
pub fn clone(self: Self, allocator: Allocator) Allocator.Error!Self {
if (@sizeOf(Context) != 0)
@compileError("Cannot infer context " ++ @typeName(Context) ++ ", call cloneContext instead.");
return self.cloneContext(allocator, @as(Context, undefined));
}
pub fn cloneContext(self: Self, allocator: Allocator, new_ctx: anytype) Allocator.Error!HashMapUnmanaged(K, V, @TypeOf(new_ctx), max_load_percentage) {
var other = HashMapUnmanaged(K, V, @TypeOf(new_ctx), max_load_percentage){};
if (self.size == 0)
return other;
const new_cap = capacityForSize(self.size);
try other.allocate(allocator, new_cap);
other.initMetadatas();
other.available = @as(u32, @truncate((new_cap * max_load_percentage) / 100));
var i: Size = 0;
var metadata = self.metadata.?;
var keys_ptr = self.keys();
var values_ptr = self.values();
while (i < self.capacity()) : (i += 1) {
if (metadata[i].isUsed()) {
other.putAssumeCapacityNoClobberContext(keys_ptr[i], values_ptr[i], new_ctx);
if (other.size == self.size)
break;
}
}
return other;
}
/// Set the map to an empty state, making deinitialization a no-op, and
/// returning a copy of the original.
pub fn move(self: *Self) Self {
const result = self.*;
self.* = .{};
return result;
}
fn grow(self: *Self, allocator: Allocator, new_capacity: Size, ctx: Context) Allocator.Error!void {
@setCold(true);
const new_cap = @max(new_capacity, minimal_capacity);
assert(new_cap > self.capacity());
assert(std.math.isPowerOfTwo(new_cap));
var map = Self{};
defer map.deinit(allocator);
try map.allocate(allocator, new_cap);
map.initMetadatas();
map.available = @as(u32, @truncate((new_cap * max_load_percentage) / 100));
if (self.size != 0) {
const old_capacity = self.capacity();
var i: Size = 0;
var metadata = self.metadata.?;
var keys_ptr = self.keys();
var values_ptr = self.values();
while (i < old_capacity) : (i += 1) {
if (metadata[i].isUsed()) {
map.putAssumeCapacityNoClobberContext(keys_ptr[i], values_ptr[i], ctx);
if (map.size == self.size)
break;
}
}
}
self.size = 0;
std.mem.swap(Self, self, &map);
}
fn allocate(self: *Self, allocator: Allocator, new_capacity: Size) Allocator.Error!void {
const header_align = @alignOf(Header);
const key_align = if (@sizeOf(K) == 0) 1 else @alignOf(K);
const val_align = if (@sizeOf(V) == 0) 1 else @alignOf(V);
const max_align = comptime @max(header_align, key_align, val_align);
const meta_size = @sizeOf(Header) + new_capacity * @sizeOf(Metadata);
comptime assert(@alignOf(Metadata) == 1);
const keys_start = std.mem.alignForward(usize, meta_size, key_align);
const keys_end = keys_start + new_capacity * @sizeOf(K);
const vals_start = std.mem.alignForward(usize, keys_end, val_align);
const vals_end = vals_start + new_capacity * @sizeOf(V);
const total_size = std.mem.alignForward(usize, vals_end, max_align);
const slice = try allocator.alignedAlloc(u8, max_align, total_size);
const ptr = @intFromPtr(slice.ptr);
const metadata = ptr + @sizeOf(Header);
const hdr = @as(*Header, @ptrFromInt(ptr));
if (@sizeOf([*]V) != 0) {
hdr.values = @as([*]V, @ptrFromInt(ptr + vals_start));
}
if (@sizeOf([*]K) != 0) {
hdr.keys = @as([*]K, @ptrFromInt(ptr + keys_start));
}
hdr.capacity = new_capacity;
self.metadata = @as([*]Metadata, @ptrFromInt(metadata));
}
fn deallocate(self: *Self, allocator: Allocator) void {
if (self.metadata == null) return;
const header_align = @alignOf(Header);
const key_align = if (@sizeOf(K) == 0) 1 else @alignOf(K);
const val_align = if (@sizeOf(V) == 0) 1 else @alignOf(V);
const max_align = comptime @max(header_align, key_align, val_align);
const cap = self.capacity();
const meta_size = @sizeOf(Header) + cap * @sizeOf(Metadata);
comptime assert(@alignOf(Metadata) == 1);
const keys_start = std.mem.alignForward(usize, meta_size, key_align);
const keys_end = keys_start + cap * @sizeOf(K);
const vals_start = std.mem.alignForward(usize, keys_end, val_align);
const vals_end = vals_start + cap * @sizeOf(V);
const total_size = std.mem.alignForward(usize, vals_end, max_align);
const slice = @as([*]align(max_align) u8, @ptrFromInt(@intFromPtr(self.header())))[0..total_size];
allocator.free(slice);
self.metadata = null;
self.available = 0;
}
/// This function is used in the debugger pretty formatters in tools/ to fetch the
/// header type to facilitate fancy debug printing for this type.
fn dbHelper(self: *Self, hdr: *Header, entry: *Entry) void {
_ = self;
_ = hdr;
_ = entry;
}
comptime {
if (builtin.mode == .Debug) {
_ = &dbHelper;
}
}
};
}
const testing = std.testing;
const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
test "std.hash_map basic usage" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
const count = 5;
var i: u32 = 0;
var total: u32 = 0;
while (i < count) : (i += 1) {
try map.put(i, i);
total += i;
}
var sum: u32 = 0;
var it = map.iterator();
while (it.next()) |kv| {
sum += kv.key_ptr.*;
}
try expectEqual(total, sum);
i = 0;
sum = 0;
while (i < count) : (i += 1) {
try expectEqual(i, map.get(i).?);
sum += map.get(i).?;
}
try expectEqual(total, sum);
}
test "std.hash_map ensureTotalCapacity" {
var map = AutoHashMap(i32, i32).init(std.testing.allocator);
defer map.deinit();
try map.ensureTotalCapacity(20);
const initial_capacity = map.capacity();
try testing.expect(initial_capacity >= 20);
var i: i32 = 0;
while (i < 20) : (i += 1) {
try testing.expect(map.fetchPutAssumeCapacity(i, i + 10) == null);
}
// shouldn't resize from putAssumeCapacity
try testing.expect(initial_capacity == map.capacity());
}
test "std.hash_map ensureUnusedCapacity with tombstones" {
var map = AutoHashMap(i32, i32).init(std.testing.allocator);
defer map.deinit();
var i: i32 = 0;
while (i < 100) : (i += 1) {
try map.ensureUnusedCapacity(1);
map.putAssumeCapacity(i, i);
_ = map.remove(i);
}
}
test "std.hash_map clearRetainingCapacity" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
map.clearRetainingCapacity();
try map.put(1, 1);
try expectEqual(map.get(1).?, 1);
try expectEqual(map.count(), 1);
map.clearRetainingCapacity();
map.putAssumeCapacity(1, 1);
try expectEqual(map.get(1).?, 1);
try expectEqual(map.count(), 1);
const cap = map.capacity();
try expect(cap > 0);
map.clearRetainingCapacity();
map.clearRetainingCapacity();
try expectEqual(map.count(), 0);
try expectEqual(map.capacity(), cap);
try expect(!map.contains(1));
}
test "std.hash_map grow" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
const growTo = 12456;
var i: u32 = 0;
while (i < growTo) : (i += 1) {
try map.put(i, i);
}
try expectEqual(map.count(), growTo);
i = 0;
var it = map.iterator();
while (it.next()) |kv| {
try expectEqual(kv.key_ptr.*, kv.value_ptr.*);
i += 1;
}
try expectEqual(i, growTo);
i = 0;
while (i < growTo) : (i += 1) {
try expectEqual(map.get(i).?, i);
}
}
test "std.hash_map clone" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
var a = try map.clone();
defer a.deinit();
try expectEqual(a.count(), 0);
try a.put(1, 1);
try a.put(2, 2);
try a.put(3, 3);
var b = try a.clone();
defer b.deinit();
try expectEqual(b.count(), 3);
try expectEqual(b.get(1).?, 1);
try expectEqual(b.get(2).?, 2);
try expectEqual(b.get(3).?, 3);
var original = AutoHashMap(i32, i32).init(std.testing.allocator);
defer original.deinit();
var i: u8 = 0;
while (i < 10) : (i += 1) {
try original.putNoClobber(i, i * 10);
}
var copy = try original.clone();
defer copy.deinit();
i = 0;
while (i < 10) : (i += 1) {
try testing.expect(copy.get(i).? == i * 10);
}
}
test "std.hash_map ensureTotalCapacity with existing elements" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
try map.put(0, 0);
try expectEqual(map.count(), 1);
try expectEqual(map.capacity(), @TypeOf(map).Unmanaged.minimal_capacity);
try map.ensureTotalCapacity(65);
try expectEqual(map.count(), 1);
try expectEqual(map.capacity(), 128);
}
test "std.hash_map ensureTotalCapacity satisfies max load factor" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
try map.ensureTotalCapacity(127);
try expectEqual(map.capacity(), 256);
}
test "std.hash_map remove" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
var i: u32 = 0;
while (i < 16) : (i += 1) {
try map.put(i, i);
}
i = 0;
while (i < 16) : (i += 1) {
if (i % 3 == 0) {
_ = map.remove(i);
}
}
try expectEqual(map.count(), 10);
var it = map.iterator();
while (it.next()) |kv| {
try expectEqual(kv.key_ptr.*, kv.value_ptr.*);
try expect(kv.key_ptr.* % 3 != 0);
}
i = 0;
while (i < 16) : (i += 1) {
if (i % 3 == 0) {
try expect(!map.contains(i));
} else {
try expectEqual(map.get(i).?, i);
}
}
}
test "std.hash_map reverse removes" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
var i: u32 = 0;
while (i < 16) : (i += 1) {
try map.putNoClobber(i, i);
}
i = 16;
while (i > 0) : (i -= 1) {
_ = map.remove(i - 1);
try expect(!map.contains(i - 1));
var j: u32 = 0;
while (j < i - 1) : (j += 1) {
try expectEqual(map.get(j).?, j);
}
}
try expectEqual(map.count(), 0);
}
test "std.hash_map multiple removes on same metadata" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
var i: u32 = 0;
while (i < 16) : (i += 1) {
try map.put(i, i);
}
_ = map.remove(7);
_ = map.remove(15);
_ = map.remove(14);
_ = map.remove(13);
try expect(!map.contains(7));
try expect(!map.contains(15));
try expect(!map.contains(14));
try expect(!map.contains(13));
i = 0;
while (i < 13) : (i += 1) {
if (i == 7) {
try expect(!map.contains(i));
} else {
try expectEqual(map.get(i).?, i);
}
}
try map.put(15, 15);
try map.put(13, 13);
try map.put(14, 14);
try map.put(7, 7);
i = 0;
while (i < 16) : (i += 1) {
try expectEqual(map.get(i).?, i);
}
}
test "std.hash_map put and remove loop in random order" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
var keys = std.ArrayList(u32).init(std.testing.allocator);
defer keys.deinit();
const size = 32;
const iterations = 100;
var i: u32 = 0;
while (i < size) : (i += 1) {
try keys.append(i);
}
var prng = std.rand.DefaultPrng.init(0);
const random = prng.random();
while (i < iterations) : (i += 1) {
random.shuffle(u32, keys.items);
for (keys.items) |key| {
try map.put(key, key);
}
try expectEqual(map.count(), size);
for (keys.items) |key| {
_ = map.remove(key);
}
try expectEqual(map.count(), 0);
}
}
test "std.hash_map remove one million elements in random order" {
const Map = AutoHashMap(u32, u32);
const n = 1000 * 1000;
var map = Map.init(std.heap.page_allocator);
defer map.deinit();
var keys = std.ArrayList(u32).init(std.heap.page_allocator);
defer keys.deinit();
var i: u32 = 0;
while (i < n) : (i += 1) {
keys.append(i) catch unreachable;
}
var prng = std.rand.DefaultPrng.init(0);
const random = prng.random();
random.shuffle(u32, keys.items);
for (keys.items) |key| {
map.put(key, key) catch unreachable;
}
random.shuffle(u32, keys.items);
i = 0;
while (i < n) : (i += 1) {
const key = keys.items[i];
_ = map.remove(key);
}
}
test "std.hash_map put" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
var i: u32 = 0;
while (i < 16) : (i += 1) {
try map.put(i, i);
}
i = 0;
while (i < 16) : (i += 1) {
try expectEqual(map.get(i).?, i);
}
i = 0;
while (i < 16) : (i += 1) {
try map.put(i, i * 16 + 1);
}
i = 0;
while (i < 16) : (i += 1) {
try expectEqual(map.get(i).?, i * 16 + 1);
}
}
test "std.hash_map putAssumeCapacity" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
try map.ensureTotalCapacity(20);
var i: u32 = 0;
while (i < 20) : (i += 1) {
map.putAssumeCapacityNoClobber(i, i);
}
i = 0;
var sum = i;
while (i < 20) : (i += 1) {
sum += map.getPtr(i).?.*;
}
try expectEqual(sum, 190);
i = 0;
while (i < 20) : (i += 1) {
map.putAssumeCapacity(i, 1);
}
i = 0;
sum = i;
while (i < 20) : (i += 1) {
sum += map.get(i).?;
}
try expectEqual(sum, 20);
}
test "std.hash_map repeat putAssumeCapacity/remove" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
try map.ensureTotalCapacity(20);
const limit = map.unmanaged.available;
var i: u32 = 0;
while (i < limit) : (i += 1) {
map.putAssumeCapacityNoClobber(i, i);
}
// Repeatedly delete/insert an entry without resizing the map.
// Put to different keys so entries don't land in the just-freed slot.
i = 0;
while (i < 10 * limit) : (i += 1) {
try testing.expect(map.remove(i));
if (i % 2 == 0) {
map.putAssumeCapacityNoClobber(limit + i, i);
} else {
map.putAssumeCapacity(limit + i, i);
}
}
i = 9 * limit;
while (i < 10 * limit) : (i += 1) {
try expectEqual(map.get(limit + i), i);
}
try expectEqual(map.unmanaged.available, 0);
try expectEqual(map.unmanaged.count(), limit);
}
test "std.hash_map getOrPut" {
var map = AutoHashMap(u32, u32).init(std.testing.allocator);
defer map.deinit();
var i: u32 = 0;
while (i < 10) : (i += 1) {
try map.put(i * 2, 2);
}
i = 0;
while (i < 20) : (i += 1) {
_ = try map.getOrPutValue(i, 1);
}
i = 0;
var sum = i;
while (i < 20) : (i += 1) {
sum += map.get(i).?;
}
try expectEqual(sum, 30);
}
test "std.hash_map basic hash map usage" {
var map = AutoHashMap(i32, i32).init(std.testing.allocator);
defer map.deinit();
try testing.expect((try map.fetchPut(1, 11)) == null);
try testing.expect((try map.fetchPut(2, 22)) == null);
try testing.expect((try map.fetchPut(3, 33)) == null);
try testing.expect((try map.fetchPut(4, 44)) == null);
try map.putNoClobber(5, 55);
try testing.expect((try map.fetchPut(5, 66)).?.value == 55);
try testing.expect((try map.fetchPut(5, 55)).?.value == 66);
const gop1 = try map.getOrPut(5);
try testing.expect(gop1.found_existing == true);
try testing.expect(gop1.value_ptr.* == 55);
gop1.value_ptr.* = 77;
try testing.expect(map.getEntry(5).?.value_ptr.* == 77);
const gop2 = try map.getOrPut(99);
try testing.expect(gop2.found_existing == false);
gop2.value_ptr.* = 42;
try testing.expect(map.getEntry(99).?.value_ptr.* == 42);
const gop3 = try map.getOrPutValue(5, 5);
try testing.expect(gop3.value_ptr.* == 77);
const gop4 = try map.getOrPutValue(100, 41);
try testing.expect(gop4.value_ptr.* == 41);
try testing.expect(map.contains(2));
try testing.expect(map.getEntry(2).?.value_ptr.* == 22);
try testing.expect(map.get(2).? == 22);
const rmv1 = map.fetchRemove(2);
try testing.expect(rmv1.?.key == 2);
try testing.expect(rmv1.?.value == 22);
try testing.expect(map.fetchRemove(2) == null);
try testing.expect(map.remove(2) == false);
try testing.expect(map.getEntry(2) == null);
try testing.expect(map.get(2) == null);
try testing.expect(map.remove(3) == true);
}
test "std.hash_map getOrPutAdapted" {
const AdaptedContext = struct {
fn eql(self: @This(), adapted_key: []const u8, test_key: u64) bool {
_ = self;
return std.fmt.parseInt(u64, adapted_key, 10) catch unreachable == test_key;
}
fn hash(self: @This(), adapted_key: []const u8) u64 {
_ = self;
const key = std.fmt.parseInt(u64, adapted_key, 10) catch unreachable;
return (AutoContext(u64){}).hash(key);
}
};
var map = AutoHashMap(u64, u64).init(testing.allocator);
defer map.deinit();
const keys = [_][]const u8{
"1231",
"4564",
"7894",
"1132",
"65235",
"95462",
"0112305",
"00658",
"0",
"2",
};
var real_keys: [keys.len]u64 = undefined;
inline for (keys, 0..) |key_str, i| {
const result = try map.getOrPutAdapted(key_str, AdaptedContext{});
try testing.expect(!result.found_existing);
real_keys[i] = std.fmt.parseInt(u64, key_str, 10) catch unreachable;
result.key_ptr.* = real_keys[i];
result.value_ptr.* = i * 2;
}
try testing.expectEqual(map.count(), keys.len);
inline for (keys, 0..) |key_str, i| {
const result = map.getOrPutAssumeCapacityAdapted(key_str, AdaptedContext{});
try testing.expect(result.found_existing);
try testing.expectEqual(real_keys[i], result.key_ptr.*);
try testing.expectEqual(@as(u64, i) * 2, result.value_ptr.*);
try testing.expectEqual(real_keys[i], map.getKeyAdapted(key_str, AdaptedContext{}).?);
}
}
test "std.hash_map ensureUnusedCapacity" {
var map = AutoHashMap(u64, u64).init(testing.allocator);
defer map.deinit();
try map.ensureUnusedCapacity(32);
const capacity = map.capacity();
try map.ensureUnusedCapacity(32);
// Repeated ensureUnusedCapacity() calls with no insertions between
// should not change the capacity.
try testing.expectEqual(capacity, map.capacity());
}
test "std.hash_map removeByPtr" {
var map = AutoHashMap(i32, u64).init(testing.allocator);
defer map.deinit();
var i: i32 = undefined;
i = 0;
while (i < 10) : (i += 1) {
try map.put(i, 0);
}
try testing.expect(map.count() == 10);
i = 0;
while (i < 10) : (i += 1) {
const keyPtr = map.getKeyPtr(i);
try testing.expect(keyPtr != null);
if (keyPtr) |ptr| {
map.removeByPtr(ptr);
}
}
try testing.expect(map.count() == 0);
}
test "std.hash_map removeByPtr 0 sized key" {
var map = AutoHashMap(u0, u64).init(testing.allocator);
defer map.deinit();
try map.put(0, 0);
try testing.expect(map.count() == 1);
const keyPtr = map.getKeyPtr(0);
try testing.expect(keyPtr != null);
if (keyPtr) |ptr| {
map.removeByPtr(ptr);
}
try testing.expect(map.count() == 0);
}
test "std.hash_map repeat fetchRemove" {
var map = AutoHashMapUnmanaged(u64, void){};
defer map.deinit(testing.allocator);
try map.ensureTotalCapacity(testing.allocator, 4);
map.putAssumeCapacity(0, {});
map.putAssumeCapacity(1, {});
map.putAssumeCapacity(2, {});
map.putAssumeCapacity(3, {});
// fetchRemove() should make slots available.
var i: usize = 0;
while (i < 10) : (i += 1) {
try testing.expect(map.fetchRemove(3) != null);
map.putAssumeCapacity(3, {});
}
try testing.expect(map.get(0) != null);
try testing.expect(map.get(1) != null);
try testing.expect(map.get(2) != null);
try testing.expect(map.get(3) != null);
}