-/* $Id: hash.c,v 1.11 2001/11/02 00:57:04 brianp Exp $ */
+/**
+ * \file hash.c
+ * Generic hash table.
+ *
+ * Used for display lists and texture objects. The hash functions are
+ * thread-safe.
+ *
+ * \note key=0 is illegal.
+ *
+ * \author Brian Paul
+ */
/*
* Mesa 3-D graphics library
- * Version: 3.5
+ * Version: 4.1
*
- * Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
+ * Copyright (C) 1999-2002 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
*/
-#ifdef PC_HEADER
-#include "all.h"
-#else
#include "glheader.h"
+#include "imports.h"
#include "glthread.h"
#include "hash.h"
-#include "mem.h"
-#endif
+#include "context.h"
-/*
- * Generic hash table.
+#define TABLE_SIZE 1023 /**< Size of lookup table/array */
+
+/**
+ * An entry in the hash table.
*
- * This is used to implement display list and texture object lookup.
- * NOTE: key=0 is illegal.
+ * This struct is private to this file.
*/
-
-
-#define TABLE_SIZE 1024
-
struct HashEntry {
- GLuint Key;
- void *Data;
- struct HashEntry *Next;
+ GLuint Key; /**< the entry's key */
+ void *Data; /**< the entry's data */
+ struct HashEntry *Next; /**< pointer to next entry */
};
+/**
+ * The hash table data structure.
+ *
+ * This is an opaque types (it's not defined in hash.h file).
+ */
struct _mesa_HashTable {
- struct HashEntry *Table[TABLE_SIZE];
- GLuint MaxKey;
- _glthread_Mutex Mutex;
+ struct HashEntry *Table[TABLE_SIZE]; /**< the lookup table */
+ GLuint MaxKey; /**< highest key inserted so far */
+ _glthread_Mutex Mutex; /**< mutual exclusion lock */
};
-/*
- * Return pointer to a new, empty hash table.
+/**
+ * Create a new hash table.
+ *
+ * \return pointer to a new, empty hash table.
*/
struct _mesa_HashTable *_mesa_NewHashTable(void)
{
-/*
+/**
* Delete a hash table.
+ *
+ * \param table the hash table to delete.
+ *
+ * Frees each entry on the hash table and then the hash table structure itself.
*/
void _mesa_DeleteHashTable(struct _mesa_HashTable *table)
{
entry = next;
}
}
+ _glthread_DESTROY_MUTEX(table->Mutex);
FREE(table);
}
-/*
+/**
* Lookup an entry in the hash table.
- * Input: table - the hash table
- * key - the key
- * Return: user data pointer or NULL if key not in table
+ *
+ * \param table the hash table.
+ * \param key the key.
+ *
+ * \return pointer to user's data or NULL if key not in table
+ *
+ * Walks through the hash entry until finding the matching key.
*/
void *_mesa_HashLookup(const struct _mesa_HashTable *table, GLuint key)
{
-/*
- * Insert into the hash table. If an entry with this key already exists
- * we'll replace the existing entry.
- * Input: table - the hash table
- * key - the key (not zero)
- * data - pointer to user data
+/**
+ * Insert into the hash table.
+ *
+ * If an entry with this key already exists we'll replace the existing entry.
+ *
+ * \param table the hash table.
+ * \param key the key (not zero).
+ * \param data pointer to user data.
+ *
+ * While holding the hash table's lock, walk through the hash entry list replacing the data if a
+ * matching key is found, or inserts a new table entry otherwise.
*/
void _mesa_HashInsert(struct _mesa_HashTable *table, GLuint key, void *data)
{
-/*
+/**
* Remove an entry from the hash table.
- * Input: table - the hash table
- * key - key of entry to remove
+ *
+ * \param table the hash table.
+ * \param key key of entry to remove.
+ *
+ * While holding the hash table's lock, searches the entry with the matching
+ * key and unlinks it.
*/
void _mesa_HashRemove(struct _mesa_HashTable *table, GLuint key)
{
-/*
- * Return the key of the "first" entry in the hash table.
+/**
+ * Get the key of the "first" entry in the hash table.
+ *
* This is used in the course of deleting all display lists when
* a context is destroyed.
+ *
+ * \param table the hash table
+ *
+ * \return key for the "first" entry in the hash table.
+ *
+ * While holding the lock, walks through all table positions until finding
+ * the first entry of the first non-empty one.
*/
GLuint _mesa_HashFirstEntry(struct _mesa_HashTable *table)
{
-/*
+/**
* Dump contents of hash table for debugging.
+ *
+ * \param table the hash table.
*/
void _mesa_HashPrint(const struct _mesa_HashTable *table)
{
for (i=0;i<TABLE_SIZE;i++) {
const struct HashEntry *entry = table->Table[i];
while (entry) {
- printf("%u %p\n", entry->Key, entry->Data);
+ _mesa_debug(NULL, "%u %p\n", entry->Key, entry->Data);
entry = entry->Next;
}
}
-/*
- * Find a block of 'numKeys' adjacent unused hash keys.
- * Input: table - the hash table
- * numKeys - number of keys needed
- * Return: starting key of free block or 0 if failure
+/**
+ * Find a block of adjacent unused hash keys.
+ *
+ * \param table the hash table.
+ * \param numKeys number of keys needed.
+ *
+ * \return Starting key of free block or 0 if failure.
+ *
+ * If there are enough free keys between the maximum key existing in the table
+ * (_mesa_HashTable::MaxKey) and the maximum key possible, then simply return
+ * the adjacent key. Otherwise do a full search for a free key block in the
+ * allowable key range.
*/
GLuint _mesa_HashFindFreeKeyBlock(struct _mesa_HashTable *table, GLuint numKeys)
{
int a, b, c;
struct HashTable *t;
- printf("&a = %p\n", &a);
- printf("&b = %p\n", &b);
+ _mesa_printf("&a = %p\n", &a);
+ _mesa_printf("&b = %p\n", &b);
t = _mesa_NewHashTable();
_mesa_HashInsert(t, 501, &a);
_mesa_HashInsert(t, 10, &c);
_mesa_HashInsert(t, 0xfffffff8, &b);
_mesa_HashPrint(t);
- printf("Find 501: %p\n", _mesa_HashLookup(t,501));
- printf("Find 1313: %p\n", _mesa_HashLookup(t,1313));
- printf("Find block of 100: %d\n", _mesa_HashFindFreeKeyBlock(t, 100));
+
+ _mesa_printf("Find 501: %p\n", _mesa_HashLookup(t,501));
+ _mesa_printf("Find 1313: %p\n", _mesa_HashLookup(t,1313));
+ _mesa_printf("Find block of 100: %d\n", _mesa_HashFindFreeKeyBlock(t, 100));
+
_mesa_DeleteHashTable(t);
return 0;
projects / mesa.git / blobdiff