зеркало из https://github.com/mozilla/gecko-dev.git
383 строки
14 KiB
C
383 строки
14 KiB
C
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
|
|
*
|
|
* The contents of this file are subject to the Netscape Public
|
|
* License Version 1.1 (the "License"); you may not use this file
|
|
* except in compliance with the License. You may obtain a copy of
|
|
* the License at http://www.mozilla.org/NPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS
|
|
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express oqr
|
|
* implied. See the License for the specific language governing
|
|
* rights and limitations under the License.
|
|
*
|
|
* The Original Code is Mozilla JavaScript code.
|
|
*
|
|
* The Initial Developer of the Original Code is Netscape
|
|
* Communications Corporation. Portions created by Netscape are
|
|
* Copyright (C) 1999,2000 Netscape Communications Corporation.
|
|
* All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
*
|
|
* Alternatively, the contents of this file may be used under the
|
|
* terms of the GNU Public License (the "GPL"), in which case the
|
|
* provisions of the GPL are applicable instead of those above.
|
|
* If you wish to allow use of your version of this file only
|
|
* under the terms of the GPL and not to allow others to use your
|
|
* version of this file under the NPL, indicate your decision by
|
|
* deleting the provisions above and replace them with the notice
|
|
* and other provisions required by the GPL. If you do not delete
|
|
* the provisions above, a recipient may use your version of this
|
|
* file under either the NPL or the GPL.
|
|
*/
|
|
|
|
#ifndef pldhash_h___
|
|
#define pldhash_h___
|
|
/*
|
|
* Double hashing, a la Knuth 6.
|
|
* GENERATED BY js/src/plify_jsdhash.sed -- DO NOT EDIT!!!
|
|
*/
|
|
#include "prtypes.h"
|
|
|
|
PR_BEGIN_EXTERN_C
|
|
|
|
/* Minimum table size, or gross entry count (net is at most .75 loaded). */
|
|
#ifndef PL_DHASH_MIN_SIZE
|
|
#define PL_DHASH_MIN_SIZE 16
|
|
#endif
|
|
|
|
/*
|
|
* Multiplicative hash uses an unsigned 32 bit integer and the golden ratio,
|
|
* expressed as a fixed-point 32-bit fraction.
|
|
*/
|
|
#define PL_DHASH_BITS 32
|
|
#define PL_DHASH_GOLDEN_RATIO 0x9E3779B9U
|
|
|
|
/* Primitive and forward-struct typedefs. */
|
|
typedef PRUint32 PLDHashNumber;
|
|
typedef struct PLDHashEntryHdr PLDHashEntryHdr;
|
|
typedef struct PLDHashEntryStub PLDHashEntryStub;
|
|
typedef struct PLDHashTable PLDHashTable;
|
|
typedef struct PLDHashTableOps PLDHashTableOps;
|
|
|
|
/*
|
|
* Table entry header structure.
|
|
*
|
|
* In order to allow in-line allocation of key and value, we do not declare
|
|
* either here. Instead, the API uses const void *key as a formal parameter,
|
|
* and asks each entry for its key when necessary via a getKey callback, used
|
|
* when growing or shrinking the table. Other callback types are defined
|
|
* below and grouped into the PLDHashTableOps structure, for single static
|
|
* initialization per hash table sub-type.
|
|
*
|
|
* Each hash table sub-type should nest the PLDHashEntryHdr structure at the
|
|
* front of its particular entry type. The keyHash member contains the result
|
|
* of multiplying the hash code returned from the hashKey callback (see below)
|
|
* by PL_DHASH_GOLDEN_RATIO. Its value is table size invariant. keyHash is
|
|
* maintained automatically by PL_DHashTableOperate -- users should never set
|
|
* it, and its only uses should be via the entry macros below.
|
|
*/
|
|
struct PLDHashEntryHdr {
|
|
PLDHashNumber keyHash; /* every entry must begin like this */
|
|
};
|
|
|
|
#define PL_DHASH_ENTRY_IS_FREE(entry) ((entry)->keyHash == 0)
|
|
#define PL_DHASH_ENTRY_IS_BUSY(entry) (!PL_DHASH_ENTRY_IS_FREE(entry))
|
|
|
|
/*
|
|
* A PLDHashTable is currently 8 words (without the PL_DHASHMETER overhead)
|
|
* on most architectures, and may be allocated on the stack or within another
|
|
* structure or class (see below for the Init and Finish functions to use).
|
|
*/
|
|
struct PLDHashTable {
|
|
PLDHashTableOps *ops; /* virtual operations, see below */
|
|
void *data; /* ops- and instance-specific data */
|
|
PRInt16 hashShift; /* multiplicative hash shift */
|
|
PRInt16 sizeLog2; /* log2(table size) */
|
|
PRUint32 sizeMask; /* PR_BITMASK(log2(table size)) */
|
|
PRUint32 entrySize; /* number of bytes in an entry */
|
|
PRUint32 entryCount; /* number of entries in table */
|
|
PRUint32 removedCount; /* removed entry sentinels in table */
|
|
char *entryStore; /* entry storage */
|
|
#ifdef PL_DHASHMETER
|
|
struct PLDHashStats {
|
|
PRUint32 searches; /* total number of table searches */
|
|
PRUint32 steps; /* hash chain links traversed */
|
|
PRUint32 hits; /* searches that found key */
|
|
PRUint32 misses; /* searches that didn't find key */
|
|
PRUint32 lookups; /* number of PL_DHASH_LOOKUPs */
|
|
PRUint32 addMisses; /* adds that miss, and do work */
|
|
PRUint32 addHits; /* adds that hit an existing entry */
|
|
PRUint32 addFailures; /* out-of-memory during add growth */
|
|
PRUint32 removeHits; /* removes that hit, and do work */
|
|
PRUint32 removeMisses; /* useless removes that miss */
|
|
PRUint32 removeEnums; /* removes done by Enumerate */
|
|
PRUint32 grows; /* table expansions */
|
|
PRUint32 shrinks; /* table contractions */
|
|
} stats;
|
|
#endif
|
|
};
|
|
|
|
#ifndef CRT_CALL
|
|
#ifdef XP_OS2_VACPP
|
|
#define CRT_CALL _Optlink
|
|
#else
|
|
#define CRT_CALL
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* Table space at entryStore is allocated and freed using these callbacks.
|
|
* The allocator should return null on error only (not if called with nbytes
|
|
* equal to 0; but note that jsdhash.c code will never call with 0 nbytes).
|
|
*/
|
|
typedef void *
|
|
(* CRT_CALL PLDHashAllocTable)(PLDHashTable *table, PRUint32 nbytes);
|
|
|
|
typedef void
|
|
(* CRT_CALL PLDHashFreeTable) (PLDHashTable *table, void *ptr);
|
|
|
|
/*
|
|
* When a table grows or shrinks, each entry is queried for its key using this
|
|
* callback. NB: in that event, entry is not in table any longer; it's in the
|
|
* old entryStore vector, which is due to be freed once all entries have been
|
|
* moved via moveEntry callbacks.
|
|
*/
|
|
typedef const void *
|
|
(* CRT_CALL PLDHashGetKey) (PLDHashTable *table, PLDHashEntryHdr *entry);
|
|
|
|
/*
|
|
* Compute the hash code for a given key to be looked up, added, or removed
|
|
* from table. A hash code may have any PLDHashNumber value.
|
|
*/
|
|
typedef PLDHashNumber
|
|
(* CRT_CALL PLDHashHashKey) (PLDHashTable *table, const void *key);
|
|
|
|
/*
|
|
* Compare the key identifying entry in table with the provided key parameter.
|
|
* Return PR_TRUE if keys match, PR_FALSE otherwise.
|
|
*/
|
|
typedef PRBool
|
|
(* CRT_CALL PLDHashMatchEntry)(PLDHashTable *table,
|
|
const PLDHashEntryHdr *entry,
|
|
const void *key);
|
|
|
|
/*
|
|
* Copy the data starting at from to the new entry storage at to. Do not add
|
|
* reference counts for any strong references in the entry, however, as this
|
|
* is a "move" operation: the old entry storage at from will be freed without
|
|
* any reference-decrementing callback shortly.
|
|
*/
|
|
typedef void
|
|
(* CRT_CALL PLDHashMoveEntry)(PLDHashTable *table,
|
|
const PLDHashEntryHdr *from,
|
|
PLDHashEntryHdr *to);
|
|
|
|
/*
|
|
* Clear the entry and drop any strong references it holds. This callback is
|
|
* invoked during a PL_DHASH_REMOVE operation (see below for operation codes),
|
|
* but only if the given key is found in the table.
|
|
*/
|
|
typedef void
|
|
(* CRT_CALL PLDHashClearEntry)(PLDHashTable *table, PLDHashEntryHdr *entry);
|
|
|
|
/*
|
|
* Called when a table (whether allocated dynamically by itself, or nested in
|
|
* a larger structure, or allocated on the stack) is finished. This callback
|
|
* allows table->ops-specific code to finalize table->data.
|
|
*/
|
|
typedef void
|
|
(* CRT_CALL PLDHashFinalize) (PLDHashTable *table);
|
|
|
|
/* Finally, the "vtable" structure for PLDHashTable. */
|
|
struct PLDHashTableOps {
|
|
PLDHashAllocTable allocTable;
|
|
PLDHashFreeTable freeTable;
|
|
PLDHashGetKey getKey;
|
|
PLDHashHashKey hashKey;
|
|
PLDHashMatchEntry matchEntry;
|
|
PLDHashMoveEntry moveEntry;
|
|
PLDHashClearEntry clearEntry;
|
|
PLDHashFinalize finalize;
|
|
};
|
|
|
|
/*
|
|
* Default implementations for the above ops.
|
|
*/
|
|
PR_EXTERN(void *)
|
|
PL_DHashAllocTable(PLDHashTable *table, PRUint32 nbytes);
|
|
|
|
PR_EXTERN(void)
|
|
PL_DHashFreeTable(PLDHashTable *table, void *ptr);
|
|
|
|
PR_EXTERN(PLDHashNumber)
|
|
PL_DHashStringKey(PLDHashTable *table, const void *key);
|
|
|
|
/* A minimal entry contains a keyHash header and a void key pointer. */
|
|
struct PLDHashEntryStub {
|
|
PLDHashEntryHdr hdr;
|
|
const void *key;
|
|
};
|
|
|
|
PR_EXTERN(const void *)
|
|
PL_DHashGetKeyStub(PLDHashTable *table, PLDHashEntryHdr *entry);
|
|
|
|
PR_EXTERN(PLDHashNumber)
|
|
PL_DHashVoidPtrKeyStub(PLDHashTable *table, const void *key);
|
|
|
|
PR_EXTERN(PRBool)
|
|
PL_DHashMatchEntryStub(PLDHashTable *table,
|
|
const PLDHashEntryHdr *entry,
|
|
const void *key);
|
|
|
|
PR_EXTERN(void)
|
|
PL_DHashMoveEntryStub(PLDHashTable *table,
|
|
const PLDHashEntryHdr *from,
|
|
PLDHashEntryHdr *to);
|
|
|
|
PR_EXTERN(void)
|
|
PL_DHashClearEntryStub(PLDHashTable *table, PLDHashEntryHdr *entry);
|
|
|
|
PR_EXTERN(void)
|
|
PL_DHashFinalizeStub(PLDHashTable *table);
|
|
|
|
/*
|
|
* If you use PLDHashEntryStub or a subclass of it as your entry struct, and
|
|
* if your entries move via memcpy and clear via memset(0), you can use these
|
|
* stub operations.
|
|
*/
|
|
PR_EXTERN(PLDHashTableOps *)
|
|
PL_DHashGetStubOps(void);
|
|
|
|
/*
|
|
* Dynamically allocate a new PLDHashTable using malloc, initialize it using
|
|
* PL_DHashTableInit, and return its address. Return null on malloc failure.
|
|
* Note that the entry storage at table->entryStore will be allocated using
|
|
* the ops->allocTable callback.
|
|
*/
|
|
PR_EXTERN(PLDHashTable *)
|
|
PR_NewDHashTable(PLDHashTableOps *ops, void *data, PRUint32 entrySize,
|
|
PRUint32 capacity);
|
|
|
|
/*
|
|
* Finalize table's data, free its entry storage (via table->ops->freeTable),
|
|
* and return the memory starting at table to the malloc heap.
|
|
*/
|
|
PR_EXTERN(void)
|
|
PL_DHashTableDestroy(PLDHashTable *table);
|
|
|
|
/*
|
|
* Initialize table with ops, data, entrySize, and capacity. Capacity is a
|
|
* guess for the smallest table size at which the table will usually be less
|
|
* than 75% loaded (the table will grow or shrink as needed; capacity serves
|
|
* only to avoid inevitable early growth from PL_DHASH_MIN_SIZE).
|
|
*/
|
|
PR_EXTERN(PRBool)
|
|
PL_DHashTableInit(PLDHashTable *table, PLDHashTableOps *ops, void *data,
|
|
PRUint32 entrySize, PRUint32 capacity);
|
|
|
|
/*
|
|
* Finalize table's data, free its entry storage using table->ops->freeTable,
|
|
* and leave its members unchanged from their last live values (which leaves
|
|
* pointers dangling). If you want to burn cycles clearing table, it's up to
|
|
* your code to call memset.
|
|
*/
|
|
PR_EXTERN(void)
|
|
PL_DHashTableFinish(PLDHashTable *table);
|
|
|
|
/*
|
|
* To consolidate keyHash computation and table grow/shrink code, we use a
|
|
* single entry point for lookup, add, and remove operations. The operation
|
|
* codes are declared here, along with codes returned by PLDHashEnumerator
|
|
* functions, which control PL_DHashTableEnumerate's behavior.
|
|
*/
|
|
typedef enum PLDHashOperator {
|
|
PL_DHASH_LOOKUP = 0, /* lookup entry */
|
|
PL_DHASH_ADD = 1, /* add entry */
|
|
PL_DHASH_REMOVE = 2, /* remove entry, or enumerator says remove */
|
|
PL_DHASH_NEXT = 0, /* enumerator says continue */
|
|
PL_DHASH_STOP = 1 /* enumerator says stop */
|
|
} PLDHashOperator;
|
|
|
|
/*
|
|
* To lookup a key in table, call:
|
|
*
|
|
* entry = PL_DHashTableOperate(table, key, PL_DHASH_LOOKUP);
|
|
*
|
|
* If PL_DHASH_ENTRY_IS_BUSY(entry) is true, key was found and it identifies
|
|
* entry. If PL_DHASH_ENTRY_IS_FREE(entry) is true, key was not found.
|
|
*
|
|
* To add an entry identified by key to table, call:
|
|
*
|
|
* entry = PL_DHashTableOperate(table, key, PL_DHASH_ADD);
|
|
*
|
|
* If entry is null upon return, the table is severely overloaded, and new
|
|
* memory can't be allocated for new entry storage via table->ops->allocTable.
|
|
* Otherwise, entry->keyHash has been set so that PL_DHASH_ENTRY_IS_BUSY(entry)
|
|
* is true, and it is up to the caller to initialize the key and value parts
|
|
* of the entry sub-type, if they have not been set already (i.e. if entry was
|
|
* not already in the table).
|
|
*
|
|
* To remove an entry identified by key from table, call:
|
|
*
|
|
* (void) PL_DHashTableOperate(table, key, PL_DHASH_REMOVE);
|
|
*
|
|
* If key's entry is found, it is cleared (via table->ops->clearEntry) and
|
|
* the entry is marked so that PL_DHASH_ENTRY_IS_FREE(entry). This operation
|
|
* returns null unconditionally; you should ignore its return value.
|
|
*/
|
|
PR_EXTERN(PLDHashEntryHdr *)
|
|
PL_DHashTableOperate(PLDHashTable *table, const void *key, PLDHashOperator op);
|
|
|
|
/*
|
|
* Remove an entry already accessed via LOOKUP or ADD.
|
|
*
|
|
* NB: this is a "raw" or low-level routine, intended to be used only where
|
|
* the inefficiency of a full PL_DHashTableOperate (which rehashes in order
|
|
* to find the entry given its key) is not tolerable. This function does not
|
|
* shrink the table if it is underloaded. It does not update stats #ifdef
|
|
* PL_DHASHMETER, either.
|
|
*/
|
|
PR_EXTERN(void)
|
|
PL_DHashTableRawRemove(PLDHashTable *table, PLDHashEntryHdr *entry);
|
|
|
|
/*
|
|
* Enumerate entries in table using etor:
|
|
*
|
|
* count = PL_DHashTableEnumerate(table, etor, arg);
|
|
*
|
|
* PL_DHashTableEnumerate calls etor like so:
|
|
*
|
|
* op = etor(table, entry, number, arg);
|
|
*
|
|
* where number is a zero-based ordinal assigned to live entries according to
|
|
* their order in table->entryStore.
|
|
*
|
|
* The return value, op, is treated as a set of flags. If op is PL_DHASH_NEXT,
|
|
* then continue enumerating. If op contains PL_DHASH_REMOVE, then clear (via
|
|
* table->ops->clearEntry) and free entry. Then we check whether op contains
|
|
* PL_DHASH_STOP; if so, stop enumerating and return the number of live entries
|
|
* that were enumerated so far. Return the total number of live entries when
|
|
* enumeration completes normally.
|
|
*
|
|
* If etor calls PL_DHashTableOperate on table, it must return PL_DHASH_STOP;
|
|
* otherwise undefined behavior results.
|
|
*/
|
|
typedef PLDHashOperator
|
|
(* CRT_CALL PLDHashEnumerator)(PLDHashTable *table, PLDHashEntryHdr *hdr,
|
|
PRUint32 number, void *arg);
|
|
|
|
PR_EXTERN(PRUint32)
|
|
PL_DHashTableEnumerate(PLDHashTable *table, PLDHashEnumerator etor, void *arg);
|
|
|
|
#ifdef PL_DHASHMETER
|
|
#include <stdio.h>
|
|
|
|
PR_EXTERN(void)
|
|
PL_DHashTableDumpMeter(PLDHashTable *table, PLDHashEnumerator dump, FILE *fp);
|
|
#endif
|
|
|
|
PR_END_EXTERN_C
|
|
|
|
#endif /* pldhash_h___ */
|