2c3632d14f
Lots of code refactoring, simplification and cleanup. Lots of new unit-tests providing much higher code coverage. All courtesy of rillig at netbsd. Other significant changes: o new read-only variable .SHELL which provides the path of the shell used to run scripts (as defined by the .SHELL target). o variable parsing detects more errors. o new debug option -dl: LINT mode, does the equivalent of := for all variable assignments so that file and line number are reported for variable parse errors.
405 lines
11 KiB
C
405 lines
11 KiB
C
/* $NetBSD: hash.c,v 1.29 2020/09/01 21:11:31 rillig Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Adam de Boor.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
/*
|
|
* Copyright (c) 1988, 1989 by Adam de Boor
|
|
* Copyright (c) 1989 by Berkeley Softworks
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Adam de Boor.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef MAKE_NATIVE
|
|
static char rcsid[] = "$NetBSD: hash.c,v 1.29 2020/09/01 21:11:31 rillig Exp $";
|
|
#else
|
|
#include <sys/cdefs.h>
|
|
#ifndef lint
|
|
#if 0
|
|
static char sccsid[] = "@(#)hash.c 8.1 (Berkeley) 6/6/93";
|
|
#else
|
|
__RCSID("$NetBSD: hash.c,v 1.29 2020/09/01 21:11:31 rillig Exp $");
|
|
#endif
|
|
#endif /* not lint */
|
|
#endif
|
|
|
|
/* hash.c --
|
|
*
|
|
* This module contains routines to manipulate a hash table.
|
|
* See hash.h for a definition of the structure of the hash
|
|
* table. Hash tables grow automatically as the amount of
|
|
* information increases.
|
|
*/
|
|
#include "make.h"
|
|
|
|
/*
|
|
* Forward references to local procedures that are used before they're
|
|
* defined:
|
|
*/
|
|
|
|
static void RebuildTable(Hash_Table *);
|
|
|
|
/*
|
|
* The following defines the ratio of # entries to # buckets
|
|
* at which we rebuild the table to make it larger.
|
|
*/
|
|
|
|
#define rebuildLimit 3
|
|
|
|
/* The hash function(s) */
|
|
|
|
#ifndef HASH
|
|
/* The default: this one matches Gosling's emacs */
|
|
#define HASH(h, key, p) do { \
|
|
for (h = 0, p = key; *p;) \
|
|
h = (h << 5) - h + *p++; \
|
|
} while (0)
|
|
|
|
#endif
|
|
|
|
/* Sets up the hash table.
|
|
*
|
|
* Input:
|
|
* t Structure to to hold the table.
|
|
* numBuckets How many buckets to create for starters. This
|
|
* number is rounded up to a power of two. If
|
|
* <= 0, a reasonable default is chosen. The
|
|
* table will grow in size later as needed.
|
|
*/
|
|
void
|
|
Hash_InitTable(Hash_Table *t, int numBuckets)
|
|
{
|
|
int i;
|
|
struct Hash_Entry **hp;
|
|
|
|
/*
|
|
* Round up the size to a power of two.
|
|
*/
|
|
if (numBuckets <= 0)
|
|
i = 16;
|
|
else {
|
|
for (i = 2; i < numBuckets; i <<= 1)
|
|
continue;
|
|
}
|
|
t->numEntries = 0;
|
|
t->maxchain = 0;
|
|
t->bucketsSize = i;
|
|
t->bucketsMask = i - 1;
|
|
t->buckets = hp = bmake_malloc(sizeof(*hp) * i);
|
|
while (--i >= 0)
|
|
*hp++ = NULL;
|
|
}
|
|
|
|
/* Removes everything from the hash table and frees up the memory space it
|
|
* occupied (except for the space in the Hash_Table structure). */
|
|
void
|
|
Hash_DeleteTable(Hash_Table *t)
|
|
{
|
|
struct Hash_Entry **hp, *h, *nexth = NULL;
|
|
int i;
|
|
|
|
for (hp = t->buckets, i = t->bucketsSize; --i >= 0;) {
|
|
for (h = *hp++; h != NULL; h = nexth) {
|
|
nexth = h->next;
|
|
free(h);
|
|
}
|
|
}
|
|
free(t->buckets);
|
|
|
|
/*
|
|
* Set up the hash table to cause memory faults on any future access
|
|
* attempts until re-initialization.
|
|
*/
|
|
t->buckets = NULL;
|
|
}
|
|
|
|
/* Searches the hash table for an entry corresponding to the key.
|
|
*
|
|
* Input:
|
|
* t Hash table to search.
|
|
* key A hash key.
|
|
*
|
|
* Results:
|
|
* Returns a pointer to the entry for key, or NULL if the table contains
|
|
* no entry for the key.
|
|
*/
|
|
Hash_Entry *
|
|
Hash_FindEntry(Hash_Table *t, const char *key)
|
|
{
|
|
Hash_Entry *e;
|
|
unsigned h;
|
|
const char *p;
|
|
int chainlen;
|
|
|
|
if (t == NULL || t->buckets == NULL) {
|
|
return NULL;
|
|
}
|
|
HASH(h, key, p);
|
|
p = key;
|
|
chainlen = 0;
|
|
#ifdef DEBUG_HASH_LOOKUP
|
|
if (DEBUG(HASH))
|
|
fprintf(debug_file, "%s: %p h=%x key=%s\n", __func__,
|
|
t, h, key);
|
|
#endif
|
|
for (e = t->buckets[h & t->bucketsMask]; e != NULL; e = e->next) {
|
|
chainlen++;
|
|
if (e->namehash == h && strcmp(e->name, p) == 0)
|
|
break;
|
|
}
|
|
if (chainlen > t->maxchain)
|
|
t->maxchain = chainlen;
|
|
return e;
|
|
}
|
|
|
|
/* Searches the hash table for an entry corresponding to the key.
|
|
* If no entry is found, then one is created.
|
|
*
|
|
* Input:
|
|
* t Hash table to search.
|
|
* key A hash key.
|
|
* newPtr Filled with TRUE if new entry created,
|
|
* FALSE otherwise.
|
|
*/
|
|
Hash_Entry *
|
|
Hash_CreateEntry(Hash_Table *t, const char *key, Boolean *newPtr)
|
|
{
|
|
Hash_Entry *e;
|
|
unsigned h;
|
|
const char *p;
|
|
int keylen;
|
|
int chainlen;
|
|
struct Hash_Entry **hp;
|
|
|
|
/*
|
|
* Hash the key. As a side effect, save the length (strlen) of the
|
|
* key in case we need to create the entry.
|
|
*/
|
|
HASH(h, key, p);
|
|
keylen = p - key;
|
|
p = key;
|
|
chainlen = 0;
|
|
#ifdef DEBUG_HASH_LOOKUP
|
|
if (DEBUG(HASH))
|
|
fprintf(debug_file, "%s: %p h=%x key=%s\n", __func__,
|
|
t, h, key);
|
|
#endif
|
|
for (e = t->buckets[h & t->bucketsMask]; e != NULL; e = e->next) {
|
|
chainlen++;
|
|
if (e->namehash == h && strcmp(e->name, p) == 0) {
|
|
if (newPtr != NULL)
|
|
*newPtr = FALSE;
|
|
break;
|
|
}
|
|
}
|
|
if (chainlen > t->maxchain)
|
|
t->maxchain = chainlen;
|
|
if (e)
|
|
return e;
|
|
|
|
/*
|
|
* The desired entry isn't there. Before allocating a new entry,
|
|
* expand the table if necessary (and this changes the resulting
|
|
* bucket chain).
|
|
*/
|
|
if (t->numEntries >= rebuildLimit * t->bucketsSize)
|
|
RebuildTable(t);
|
|
e = bmake_malloc(sizeof(*e) + keylen);
|
|
hp = &t->buckets[h & t->bucketsMask];
|
|
e->next = *hp;
|
|
*hp = e;
|
|
Hash_SetValue(e, NULL);
|
|
e->namehash = h;
|
|
(void)strcpy(e->name, p);
|
|
t->numEntries++;
|
|
|
|
if (newPtr != NULL)
|
|
*newPtr = TRUE;
|
|
return e;
|
|
}
|
|
|
|
/* Delete the given hash table entry and free memory associated with it. */
|
|
void
|
|
Hash_DeleteEntry(Hash_Table *t, Hash_Entry *e)
|
|
{
|
|
Hash_Entry **hp, *p;
|
|
|
|
if (e == NULL)
|
|
return;
|
|
for (hp = &t->buckets[e->namehash & t->bucketsMask];
|
|
(p = *hp) != NULL; hp = &p->next) {
|
|
if (p == e) {
|
|
*hp = p->next;
|
|
free(p);
|
|
t->numEntries--;
|
|
return;
|
|
}
|
|
}
|
|
(void)write(2, "bad call to Hash_DeleteEntry\n", 29);
|
|
abort();
|
|
}
|
|
|
|
/* Sets things up for enumerating all entries in the hash table.
|
|
*
|
|
* Input:
|
|
* t Table to be searched.
|
|
* searchPtr Area in which to keep state about search.
|
|
*
|
|
* Results:
|
|
* The return value is the address of the first entry in
|
|
* the hash table, or NULL if the table is empty.
|
|
*/
|
|
Hash_Entry *
|
|
Hash_EnumFirst(Hash_Table *t, Hash_Search *searchPtr)
|
|
{
|
|
searchPtr->table = t;
|
|
searchPtr->nextBucket = 0;
|
|
searchPtr->entry = NULL;
|
|
return Hash_EnumNext(searchPtr);
|
|
}
|
|
|
|
/* Returns the next entry in the hash table, or NULL if the end of the table
|
|
* is reached.
|
|
*
|
|
* Input:
|
|
* searchPtr Area used to keep state about search.
|
|
*/
|
|
Hash_Entry *
|
|
Hash_EnumNext(Hash_Search *searchPtr)
|
|
{
|
|
Hash_Entry *e;
|
|
Hash_Table *t = searchPtr->table;
|
|
|
|
/*
|
|
* The entry field points to the most recently returned
|
|
* entry, or is NULL if we are starting up. If not NULL, we have
|
|
* to start at the next one in the chain.
|
|
*/
|
|
e = searchPtr->entry;
|
|
if (e != NULL)
|
|
e = e->next;
|
|
/*
|
|
* If the chain ran out, or if we are starting up, we need to
|
|
* find the next nonempty chain.
|
|
*/
|
|
while (e == NULL) {
|
|
if (searchPtr->nextBucket >= t->bucketsSize)
|
|
return NULL;
|
|
e = t->buckets[searchPtr->nextBucket++];
|
|
}
|
|
searchPtr->entry = e;
|
|
return e;
|
|
}
|
|
|
|
/* Makes a new hash table that is larger than the old one. The entire hash
|
|
* table is moved, so any bucket numbers from the old table become invalid. */
|
|
static void
|
|
RebuildTable(Hash_Table *t)
|
|
{
|
|
Hash_Entry *e, *next = NULL, **hp, **xp;
|
|
int i, mask;
|
|
Hash_Entry **oldhp;
|
|
int oldsize;
|
|
|
|
oldhp = t->buckets;
|
|
oldsize = i = t->bucketsSize;
|
|
i <<= 1;
|
|
t->bucketsSize = i;
|
|
t->bucketsMask = mask = i - 1;
|
|
t->buckets = hp = bmake_malloc(sizeof(*hp) * i);
|
|
while (--i >= 0)
|
|
*hp++ = NULL;
|
|
for (hp = oldhp, i = oldsize; --i >= 0;) {
|
|
for (e = *hp++; e != NULL; e = next) {
|
|
next = e->next;
|
|
xp = &t->buckets[e->namehash & mask];
|
|
e->next = *xp;
|
|
*xp = e;
|
|
}
|
|
}
|
|
free(oldhp);
|
|
if (DEBUG(HASH))
|
|
fprintf(debug_file, "%s: %p size=%d entries=%d maxchain=%d\n",
|
|
__func__, t, t->bucketsSize, t->numEntries, t->maxchain);
|
|
t->maxchain = 0;
|
|
}
|
|
|
|
void
|
|
Hash_ForEach(Hash_Table *t, void (*action)(void *, void *), void *data)
|
|
{
|
|
Hash_Search search;
|
|
Hash_Entry *e;
|
|
|
|
for (e = Hash_EnumFirst(t, &search);
|
|
e != NULL;
|
|
e = Hash_EnumNext(&search))
|
|
action(Hash_GetValue(e), data);
|
|
}
|
|
|
|
void
|
|
Hash_DebugStats(Hash_Table *t, const char *name)
|
|
{
|
|
if (DEBUG(HASH))
|
|
fprintf(debug_file, "Hash_Table %s: size=%d numEntries=%d maxchain=%d\n",
|
|
name, t->bucketsSize, t->numEntries, t->maxchain);
|
|
}
|