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freeswitch/libs/apr/tables/apr_tables.c
Michael Jerris 0488a5109a add apr to in tree libs 
git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@3733 d0543943-73ff-0310-b7d9-9358b9ac24b2
2006-12-19 19:58:23 +00:00

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38 KiB
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/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Resource allocation code... the code here is responsible for making
* sure that nothing leaks.
*
* rst --- 4/95 --- 6/95
*/
#include "apr_private.h"
#include "apr_general.h"
#include "apr_pools.h"
#include "apr_tables.h"
#include "apr_strings.h"
#include "apr_lib.h"
#if APR_HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if APR_HAVE_STRING_H
#include <string.h>
#endif
#if APR_HAVE_STRINGS_H
#include <strings.h>
#endif
#if APR_POOL_DEBUG && APR_HAVE_STDIO_H
#include <stdio.h>
#endif
/*****************************************************************
* This file contains array and apr_table_t functions only.
*/
/*****************************************************************
*
* The 'array' functions...
*/
static void make_array_core(apr_array_header_t *res, apr_pool_t *p,
int nelts, int elt_size, int clear)
{
/*
* Assure sanity if someone asks for
* array of zero elts.
*/
if (nelts < 1) {
nelts = 1;
}
if (clear) {
res->elts = apr_pcalloc(p, nelts * elt_size);
}
else {
res->elts = apr_palloc(p, nelts * elt_size);
}
res->pool = p;
res->elt_size = elt_size;
res->nelts = 0; /* No active elements yet... */
res->nalloc = nelts; /* ...but this many allocated */
}
APR_DECLARE(int) apr_is_empty_array(const apr_array_header_t *a)
{
return ((a == NULL) || (a->nelts == 0));
}
APR_DECLARE(apr_array_header_t *) apr_array_make(apr_pool_t *p,
int nelts, int elt_size)
{
apr_array_header_t *res;
res = (apr_array_header_t *) apr_palloc(p, sizeof(apr_array_header_t));
make_array_core(res, p, nelts, elt_size, 1);
return res;
}
APR_DECLARE(void *) apr_array_pop(apr_array_header_t *arr)
{
if (apr_is_empty_array(arr)) {
return NULL;
}
return arr->elts + (arr->elt_size * (--arr->nelts));
}
APR_DECLARE(void *) apr_array_push(apr_array_header_t *arr)
{
if (arr->nelts == arr->nalloc) {
int new_size = (arr->nalloc <= 0) ? 1 : arr->nalloc * 2;
char *new_data;
new_data = apr_palloc(arr->pool, arr->elt_size * new_size);
memcpy(new_data, arr->elts, arr->nalloc * arr->elt_size);
memset(new_data + arr->nalloc * arr->elt_size, 0,
arr->elt_size * (new_size - arr->nalloc));
arr->elts = new_data;
arr->nalloc = new_size;
}
++arr->nelts;
return arr->elts + (arr->elt_size * (arr->nelts - 1));
}
static void *apr_array_push_noclear(apr_array_header_t *arr)
{
if (arr->nelts == arr->nalloc) {
int new_size = (arr->nalloc <= 0) ? 1 : arr->nalloc * 2;
char *new_data;
new_data = apr_palloc(arr->pool, arr->elt_size * new_size);
memcpy(new_data, arr->elts, arr->nalloc * arr->elt_size);
arr->elts = new_data;
arr->nalloc = new_size;
}
++arr->nelts;
return arr->elts + (arr->elt_size * (arr->nelts - 1));
}
APR_DECLARE(void) apr_array_cat(apr_array_header_t *dst,
const apr_array_header_t *src)
{
int elt_size = dst->elt_size;
if (dst->nelts + src->nelts > dst->nalloc) {
int new_size = (dst->nalloc <= 0) ? 1 : dst->nalloc * 2;
char *new_data;
while (dst->nelts + src->nelts > new_size) {
new_size *= 2;
}
new_data = apr_pcalloc(dst->pool, elt_size * new_size);
memcpy(new_data, dst->elts, dst->nalloc * elt_size);
dst->elts = new_data;
dst->nalloc = new_size;
}
memcpy(dst->elts + dst->nelts * elt_size, src->elts,
elt_size * src->nelts);
dst->nelts += src->nelts;
}
APR_DECLARE(apr_array_header_t *) apr_array_copy(apr_pool_t *p,
const apr_array_header_t *arr)
{
apr_array_header_t *res =
(apr_array_header_t *) apr_palloc(p, sizeof(apr_array_header_t));
make_array_core(res, p, arr->nalloc, arr->elt_size, 0);
memcpy(res->elts, arr->elts, arr->elt_size * arr->nelts);
res->nelts = arr->nelts;
memset(res->elts + res->elt_size * res->nelts, 0,
res->elt_size * (res->nalloc - res->nelts));
return res;
}
/* This cute function copies the array header *only*, but arranges
* for the data section to be copied on the first push or arraycat.
* It's useful when the elements of the array being copied are
* read only, but new stuff *might* get added on the end; we have the
* overhead of the full copy only where it is really needed.
*/
static APR_INLINE void copy_array_hdr_core(apr_array_header_t *res,
const apr_array_header_t *arr)
{
res->elts = arr->elts;
res->elt_size = arr->elt_size;
res->nelts = arr->nelts;
res->nalloc = arr->nelts; /* Force overflow on push */
}
APR_DECLARE(apr_array_header_t *)
apr_array_copy_hdr(apr_pool_t *p,
const apr_array_header_t *arr)
{
apr_array_header_t *res;
res = (apr_array_header_t *) apr_palloc(p, sizeof(apr_array_header_t));
res->pool = p;
copy_array_hdr_core(res, arr);
return res;
}
/* The above is used here to avoid consing multiple new array bodies... */
APR_DECLARE(apr_array_header_t *)
apr_array_append(apr_pool_t *p,
const apr_array_header_t *first,
const apr_array_header_t *second)
{
apr_array_header_t *res = apr_array_copy_hdr(p, first);
apr_array_cat(res, second);
return res;
}
/* apr_array_pstrcat generates a new string from the apr_pool_t containing
* the concatenated sequence of substrings referenced as elements within
* the array. The string will be empty if all substrings are empty or null,
* or if there are no elements in the array.
* If sep is non-NUL, it will be inserted between elements as a separator.
*/
APR_DECLARE(char *) apr_array_pstrcat(apr_pool_t *p,
const apr_array_header_t *arr,
const char sep)
{
char *cp, *res, **strpp;
apr_size_t len;
int i;
if (arr->nelts <= 0 || arr->elts == NULL) { /* Empty table? */
return (char *) apr_pcalloc(p, 1);
}
/* Pass one --- find length of required string */
len = 0;
for (i = 0, strpp = (char **) arr->elts; ; ++strpp) {
if (strpp && *strpp != NULL) {
len += strlen(*strpp);
}
if (++i >= arr->nelts) {
break;
}
if (sep) {
++len;
}
}
/* Allocate the required string */
res = (char *) apr_palloc(p, len + 1);
cp = res;
/* Pass two --- copy the argument strings into the result space */
for (i = 0, strpp = (char **) arr->elts; ; ++strpp) {
if (strpp && *strpp != NULL) {
len = strlen(*strpp);
memcpy(cp, *strpp, len);
cp += len;
}
if (++i >= arr->nelts) {
break;
}
if (sep) {
*cp++ = sep;
}
}
*cp = '\0';
/* Return the result string */
return res;
}
/*****************************************************************
*
* The "table" functions.
*/
#if APR_CHARSET_EBCDIC
#define CASE_MASK 0xbfbfbfbf
#else
#define CASE_MASK 0xdfdfdfdf
#endif
#define TABLE_HASH_SIZE 32
#define TABLE_INDEX_MASK 0x1f
#define TABLE_HASH(key) (TABLE_INDEX_MASK & *(unsigned char *)(key))
#define TABLE_INDEX_IS_INITIALIZED(t, i) ((t)->index_initialized & (1 << (i)))
#define TABLE_SET_INDEX_INITIALIZED(t, i) ((t)->index_initialized |= (1 << (i)))
/* Compute the "checksum" for a key, consisting of the first
* 4 bytes, normalized for case-insensitivity and packed into
* an int...this checksum allows us to do a single integer
* comparison as a fast check to determine whether we can
* skip a strcasecmp
*/
#define COMPUTE_KEY_CHECKSUM(key, checksum) \
{ \
const char *k = (key); \
apr_uint32_t c = (apr_uint32_t)*k; \
(checksum) = c; \
(checksum) <<= 8; \
if (c) { \
c = (apr_uint32_t)*++k; \
checksum |= c; \
} \
(checksum) <<= 8; \
if (c) { \
c = (apr_uint32_t)*++k; \
checksum |= c; \
} \
(checksum) <<= 8; \
if (c) { \
c = (apr_uint32_t)*++k; \
checksum |= c; \
} \
checksum &= CASE_MASK; \
}
/** The opaque string-content table type */
struct apr_table_t {
/* This has to be first to promote backwards compatibility with
* older modules which cast a apr_table_t * to an apr_array_header_t *...
* they should use the apr_table_elts() function for most of the
* cases they do this for.
*/
/** The underlying array for the table */
apr_array_header_t a;
#ifdef MAKE_TABLE_PROFILE
/** Who created the array. */
void *creator;
#endif
/* An index to speed up table lookups. The way this works is:
* - Hash the key into the index:
* - index_first[TABLE_HASH(key)] is the offset within
* the table of the first entry with that key
* - index_last[TABLE_HASH(key)] is the offset within
* the table of the last entry with that key
* - If (and only if) there is no entry in the table whose
* key hashes to index element i, then the i'th bit
* of index_initialized will be zero. (Check this before
* trying to use index_first[i] or index_last[i]!)
*/
apr_uint32_t index_initialized;
int index_first[TABLE_HASH_SIZE];
int index_last[TABLE_HASH_SIZE];
};
/*
* NOTICE: if you tweak this you should look at is_empty_table()
* and table_elts() in alloc.h
*/
#ifdef MAKE_TABLE_PROFILE
static apr_table_entry_t *table_push(apr_table_t *t)
{
if (t->a.nelts == t->a.nalloc) {
return NULL;
}
return (apr_table_entry_t *) apr_array_push_noclear(&t->a);
}
#else /* MAKE_TABLE_PROFILE */
#define table_push(t) ((apr_table_entry_t *) apr_array_push_noclear(&(t)->a))
#endif /* MAKE_TABLE_PROFILE */
APR_DECLARE(const apr_array_header_t *) apr_table_elts(const apr_table_t *t)
{
return (const apr_array_header_t *)t;
}
APR_DECLARE(int) apr_is_empty_table(const apr_table_t *t)
{
return ((t == NULL) || (t->a.nelts == 0));
}
APR_DECLARE(apr_table_t *) apr_table_make(apr_pool_t *p, int nelts)
{
apr_table_t *t = apr_palloc(p, sizeof(apr_table_t));
make_array_core(&t->a, p, nelts, sizeof(apr_table_entry_t), 0);
#ifdef MAKE_TABLE_PROFILE
t->creator = __builtin_return_address(0);
#endif
t->index_initialized = 0;
return t;
}
APR_DECLARE(apr_table_t *) apr_table_copy(apr_pool_t *p, const apr_table_t *t)
{
apr_table_t *new = apr_palloc(p, sizeof(apr_table_t));
#if APR_POOL_DEBUG
/* we don't copy keys and values, so it's necessary that t->a.pool
* have a life span at least as long as p
*/
if (!apr_pool_is_ancestor(t->a.pool, p)) {
fprintf(stderr, "apr_table_copy: t's pool is not an ancestor of p\n");
abort();
}
#endif
make_array_core(&new->a, p, t->a.nalloc, sizeof(apr_table_entry_t), 0);
memcpy(new->a.elts, t->a.elts, t->a.nelts * sizeof(apr_table_entry_t));
new->a.nelts = t->a.nelts;
memcpy(new->index_first, t->index_first, sizeof(int) * TABLE_HASH_SIZE);
memcpy(new->index_last, t->index_last, sizeof(int) * TABLE_HASH_SIZE);
new->index_initialized = t->index_initialized;
return new;
}
static void table_reindex(apr_table_t *t)
{
int i;
int hash;
apr_table_entry_t *next_elt = (apr_table_entry_t *) t->a.elts;
t->index_initialized = 0;
for (i = 0; i < t->a.nelts; i++, next_elt++) {
hash = TABLE_HASH(next_elt->key);
t->index_last[hash] = i;
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
t->index_first[hash] = i;
TABLE_SET_INDEX_INITIALIZED(t, hash);
}
}
}
APR_DECLARE(void) apr_table_clear(apr_table_t *t)
{
t->a.nelts = 0;
t->index_initialized = 0;
}
APR_DECLARE(const char *) apr_table_get(const apr_table_t *t, const char *key)
{
apr_table_entry_t *next_elt;
apr_table_entry_t *end_elt;
apr_uint32_t checksum;
int hash;
if (key == NULL) {
return NULL;
}
hash = TABLE_HASH(key);
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
return NULL;
}
COMPUTE_KEY_CHECKSUM(key, checksum);
next_elt = ((apr_table_entry_t *) t->a.elts) + t->index_first[hash];;
end_elt = ((apr_table_entry_t *) t->a.elts) + t->index_last[hash];
for (; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
return next_elt->val;
}
}
return NULL;
}
APR_DECLARE(void) apr_table_set(apr_table_t *t, const char *key,
const char *val)
{
apr_table_entry_t *next_elt;
apr_table_entry_t *end_elt;
apr_table_entry_t *table_end;
apr_uint32_t checksum;
int hash;
COMPUTE_KEY_CHECKSUM(key, checksum);
hash = TABLE_HASH(key);
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
t->index_first[hash] = t->a.nelts;
TABLE_SET_INDEX_INITIALIZED(t, hash);
goto add_new_elt;
}
next_elt = ((apr_table_entry_t *) t->a.elts) + t->index_first[hash];;
end_elt = ((apr_table_entry_t *) t->a.elts) + t->index_last[hash];
table_end =((apr_table_entry_t *) t->a.elts) + t->a.nelts;
for (; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
/* Found an existing entry with the same key, so overwrite it */
int must_reindex = 0;
apr_table_entry_t *dst_elt = NULL;
next_elt->val = apr_pstrdup(t->a.pool, val);
/* Remove any other instances of this key */
for (next_elt++; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
t->a.nelts--;
if (!dst_elt) {
dst_elt = next_elt;
}
}
else if (dst_elt) {
*dst_elt++ = *next_elt;
must_reindex = 1;
}
}
/* If we've removed anything, shift over the remainder
* of the table (note that the previous loop didn't
* run to the end of the table, just to the last match
* for the index)
*/
if (dst_elt) {
for (; next_elt < table_end; next_elt++) {
*dst_elt++ = *next_elt;
}
must_reindex = 1;
}
if (must_reindex) {
table_reindex(t);
}
return;
}
}
add_new_elt:
t->index_last[hash] = t->a.nelts;
next_elt = (apr_table_entry_t *) table_push(t);
next_elt->key = apr_pstrdup(t->a.pool, key);
next_elt->val = apr_pstrdup(t->a.pool, val);
next_elt->key_checksum = checksum;
}
APR_DECLARE(void) apr_table_setn(apr_table_t *t, const char *key,
const char *val)
{
apr_table_entry_t *next_elt;
apr_table_entry_t *end_elt;
apr_table_entry_t *table_end;
apr_uint32_t checksum;
int hash;
COMPUTE_KEY_CHECKSUM(key, checksum);
hash = TABLE_HASH(key);
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
t->index_first[hash] = t->a.nelts;
TABLE_SET_INDEX_INITIALIZED(t, hash);
goto add_new_elt;
}
next_elt = ((apr_table_entry_t *) t->a.elts) + t->index_first[hash];;
end_elt = ((apr_table_entry_t *) t->a.elts) + t->index_last[hash];
table_end =((apr_table_entry_t *) t->a.elts) + t->a.nelts;
for (; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
/* Found an existing entry with the same key, so overwrite it */
int must_reindex = 0;
apr_table_entry_t *dst_elt = NULL;
next_elt->val = (char *)val;
/* Remove any other instances of this key */
for (next_elt++; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
t->a.nelts--;
if (!dst_elt) {
dst_elt = next_elt;
}
}
else if (dst_elt) {
*dst_elt++ = *next_elt;
must_reindex = 1;
}
}
/* If we've removed anything, shift over the remainder
* of the table (note that the previous loop didn't
* run to the end of the table, just to the last match
* for the index)
*/
if (dst_elt) {
for (; next_elt < table_end; next_elt++) {
*dst_elt++ = *next_elt;
}
must_reindex = 1;
}
if (must_reindex) {
table_reindex(t);
}
return;
}
}
add_new_elt:
t->index_last[hash] = t->a.nelts;
next_elt = (apr_table_entry_t *) table_push(t);
next_elt->key = (char *)key;
next_elt->val = (char *)val;
next_elt->key_checksum = checksum;
}
APR_DECLARE(void) apr_table_unset(apr_table_t *t, const char *key)
{
apr_table_entry_t *next_elt;
apr_table_entry_t *end_elt;
apr_table_entry_t *dst_elt;
apr_uint32_t checksum;
int hash;
int must_reindex;
hash = TABLE_HASH(key);
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
return;
}
COMPUTE_KEY_CHECKSUM(key, checksum);
next_elt = ((apr_table_entry_t *) t->a.elts) + t->index_first[hash];
end_elt = ((apr_table_entry_t *) t->a.elts) + t->index_last[hash];
must_reindex = 0;
for (; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
/* Found a match: remove this entry, plus any additional
* matches for the same key that might follow
*/
apr_table_entry_t *table_end = ((apr_table_entry_t *) t->a.elts) +
t->a.nelts;
t->a.nelts--;
dst_elt = next_elt;
for (next_elt++; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
t->a.nelts--;
}
else {
*dst_elt++ = *next_elt;
}
}
/* Shift over the remainder of the table (note that
* the previous loop didn't run to the end of the table,
* just to the last match for the index)
*/
for (; next_elt < table_end; next_elt++) {
*dst_elt++ = *next_elt;
}
must_reindex = 1;
break;
}
}
if (must_reindex) {
table_reindex(t);
}
}
APR_DECLARE(void) apr_table_merge(apr_table_t *t, const char *key,
const char *val)
{
apr_table_entry_t *next_elt;
apr_table_entry_t *end_elt;
apr_uint32_t checksum;
int hash;
COMPUTE_KEY_CHECKSUM(key, checksum);
hash = TABLE_HASH(key);
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
t->index_first[hash] = t->a.nelts;
TABLE_SET_INDEX_INITIALIZED(t, hash);
goto add_new_elt;
}
next_elt = ((apr_table_entry_t *) t->a.elts) + t->index_first[hash];
end_elt = ((apr_table_entry_t *) t->a.elts) + t->index_last[hash];
for (; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
/* Found an existing entry with the same key, so merge with it */
next_elt->val = apr_pstrcat(t->a.pool, next_elt->val, ", ",
val, NULL);
return;
}
}
add_new_elt:
t->index_last[hash] = t->a.nelts;
next_elt = (apr_table_entry_t *) table_push(t);
next_elt->key = apr_pstrdup(t->a.pool, key);
next_elt->val = apr_pstrdup(t->a.pool, val);
next_elt->key_checksum = checksum;
}
APR_DECLARE(void) apr_table_mergen(apr_table_t *t, const char *key,
const char *val)
{
apr_table_entry_t *next_elt;
apr_table_entry_t *end_elt;
apr_uint32_t checksum;
int hash;
#if APR_POOL_DEBUG
{
if (!apr_pool_is_ancestor(apr_pool_find(key), t->a.pool)) {
fprintf(stderr, "apr_table_mergen: key not in ancestor pool of t\n");
abort();
}
if (!apr_pool_is_ancestor(apr_pool_find(val), t->a.pool)) {
fprintf(stderr, "apr_table_mergen: key not in ancestor pool of t\n");
abort();
}
}
#endif
COMPUTE_KEY_CHECKSUM(key, checksum);
hash = TABLE_HASH(key);
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
t->index_first[hash] = t->a.nelts;
TABLE_SET_INDEX_INITIALIZED(t, hash);
goto add_new_elt;
}
next_elt = ((apr_table_entry_t *) t->a.elts) + t->index_first[hash];;
end_elt = ((apr_table_entry_t *) t->a.elts) + t->index_last[hash];
for (; next_elt <= end_elt; next_elt++) {
if ((checksum == next_elt->key_checksum) &&
!strcasecmp(next_elt->key, key)) {
/* Found an existing entry with the same key, so merge with it */
next_elt->val = apr_pstrcat(t->a.pool, next_elt->val, ", ",
val, NULL);
return;
}
}
add_new_elt:
t->index_last[hash] = t->a.nelts;
next_elt = (apr_table_entry_t *) table_push(t);
next_elt->key = (char *)key;
next_elt->val = (char *)val;
next_elt->key_checksum = checksum;
}
APR_DECLARE(void) apr_table_add(apr_table_t *t, const char *key,
const char *val)
{
apr_table_entry_t *elts;
apr_uint32_t checksum;
int hash;
hash = TABLE_HASH(key);
t->index_last[hash] = t->a.nelts;
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
t->index_first[hash] = t->a.nelts;
TABLE_SET_INDEX_INITIALIZED(t, hash);
}
COMPUTE_KEY_CHECKSUM(key, checksum);
elts = (apr_table_entry_t *) table_push(t);
elts->key = apr_pstrdup(t->a.pool, key);
elts->val = apr_pstrdup(t->a.pool, val);
elts->key_checksum = checksum;
}
APR_DECLARE(void) apr_table_addn(apr_table_t *t, const char *key,
const char *val)
{
apr_table_entry_t *elts;
apr_uint32_t checksum;
int hash;
#if APR_POOL_DEBUG
{
if (!apr_pool_is_ancestor(apr_pool_find(key), t->a.pool)) {
fprintf(stderr, "apr_table_addn: key not in ancestor pool of t\n");
abort();
}
if (!apr_pool_is_ancestor(apr_pool_find(val), t->a.pool)) {
fprintf(stderr, "apr_table_addn: key not in ancestor pool of t\n");
abort();
}
}
#endif
hash = TABLE_HASH(key);
t->index_last[hash] = t->a.nelts;
if (!TABLE_INDEX_IS_INITIALIZED(t, hash)) {
t->index_first[hash] = t->a.nelts;
TABLE_SET_INDEX_INITIALIZED(t, hash);
}
COMPUTE_KEY_CHECKSUM(key, checksum);
elts = (apr_table_entry_t *) table_push(t);
elts->key = (char *)key;
elts->val = (char *)val;
elts->key_checksum = checksum;
}
APR_DECLARE(apr_table_t *) apr_table_overlay(apr_pool_t *p,
const apr_table_t *overlay,
const apr_table_t *base)
{
apr_table_t *res;
#if APR_POOL_DEBUG
/* we don't copy keys and values, so it's necessary that
* overlay->a.pool and base->a.pool have a life span at least
* as long as p
*/
if (!apr_pool_is_ancestor(overlay->a.pool, p)) {
fprintf(stderr,
"apr_table_overlay: overlay's pool is not an ancestor of p\n");
abort();
}
if (!apr_pool_is_ancestor(base->a.pool, p)) {
fprintf(stderr,
"apr_table_overlay: base's pool is not an ancestor of p\n");
abort();
}
#endif
res = apr_palloc(p, sizeof(apr_table_t));
/* behave like append_arrays */
res->a.pool = p;
copy_array_hdr_core(&res->a, &overlay->a);
apr_array_cat(&res->a, &base->a);
table_reindex(res);
return res;
}
/* And now for something completely abstract ...
* For each key value given as a vararg:
* run the function pointed to as
* int comp(void *r, char *key, char *value);
* on each valid key-value pair in the apr_table_t t that matches the vararg key,
* or once for every valid key-value pair if the vararg list is empty,
* until the function returns false (0) or we finish the table.
*
* Note that we restart the traversal for each vararg, which means that
* duplicate varargs will result in multiple executions of the function
* for each matching key. Note also that if the vararg list is empty,
* only one traversal will be made and will cut short if comp returns 0.
*
* Note that the table_get and table_merge functions assume that each key in
* the apr_table_t is unique (i.e., no multiple entries with the same key). This
* function does not make that assumption, since it (unfortunately) isn't
* true for some of Apache's tables.
*
* Note that rec is simply passed-on to the comp function, so that the
* caller can pass additional info for the task.
*
* ADDENDUM for apr_table_vdo():
*
* The caching api will allow a user to walk the header values:
*
* apr_status_t apr_cache_el_header_walk(apr_cache_el *el,
* int (*comp)(void *, const char *, const char *), void *rec, ...);
*
* So it can be ..., however from there I use a callback that use a va_list:
*
* apr_status_t (*cache_el_header_walk)(apr_cache_el *el,
* int (*comp)(void *, const char *, const char *), void *rec, va_list);
*
* To pass those ...'s on down to the actual module that will handle walking
* their headers, in the file case this is actually just an apr_table - and
* rather than reimplementing apr_table_do (which IMHO would be bad) I just
* called it with the va_list. For mod_shmem_cache I don't need it since I
* can't use apr_table's, but mod_file_cache should (though a good hash would
* be better, but that's a different issue :).
*
* So to make mod_file_cache easier to maintain, it's a good thing
*/
APR_DECLARE_NONSTD(int) apr_table_do(apr_table_do_callback_fn_t *comp,
void *rec, const apr_table_t *t, ...)
{
int rv;
va_list vp;
va_start(vp, t);
rv = apr_table_vdo(comp, rec, t, vp);
va_end(vp);
return rv;
}
/* XXX: do the semantics of this routine make any sense? Right now,
* if the caller passed in a non-empty va_list of keys to search for,
* the "early termination" facility only terminates on *that* key; other
* keys will continue to process. Note that this only has any effect
* at all if there are multiple entries in the table with the same key,
* otherwise the called function can never effectively early-terminate
* this function, as the zero return value is effectively ignored.
*
* Note also that this behavior is at odds with the behavior seen if an
* empty va_list is passed in -- in that case, a zero return value terminates
* the entire apr_table_vdo (which is what I think should happen in
* both cases).
*
* If nobody objects soon, I'm going to change the order of the nested
* loops in this function so that any zero return value from the (*comp)
* function will cause a full termination of apr_table_vdo. I'm hesitant
* at the moment because these (funky) semantics have been around for a
* very long time, and although Apache doesn't seem to use them at all,
* some third-party vendor might. I can only think of one possible reason
* the existing semantics would make any sense, and it's very Apache-centric,
* which is this: if (*comp) is looking for matches of a particular
* substring in request headers (let's say it's looking for a particular
* cookie name in the Set-Cookie headers), then maybe it wants to be
* able to stop searching early as soon as it finds that one and move
* on to the next key. That's only an optimization of course, but changing
* the behavior of this function would mean that any code that tried
* to do that would stop working right.
*
* Sigh. --JCW, 06/28/02
*/
APR_DECLARE(int) apr_table_vdo(apr_table_do_callback_fn_t *comp,
void *rec, const apr_table_t *t, va_list vp)
{
char *argp;
apr_table_entry_t *elts = (apr_table_entry_t *) t->a.elts;
int vdorv = 1;
argp = va_arg(vp, char *);
do {
int rv = 1, i;
if (argp) {
/* Scan for entries that match the next key */
int hash = TABLE_HASH(argp);
if (TABLE_INDEX_IS_INITIALIZED(t, hash)) {
apr_uint32_t checksum;
COMPUTE_KEY_CHECKSUM(argp, checksum);
for (i = t->index_first[hash];
rv && (i <= t->index_last[hash]); ++i) {
if (elts[i].key && (checksum == elts[i].key_checksum) &&
!strcasecmp(elts[i].key, argp)) {
rv = (*comp) (rec, elts[i].key, elts[i].val);
}
}
}
}
else {
/* Scan the entire table */
for (i = 0; rv && (i < t->a.nelts); ++i) {
if (elts[i].key) {
rv = (*comp) (rec, elts[i].key, elts[i].val);
}
}
}
if (rv == 0) {
vdorv = 0;
}
} while (argp && ((argp = va_arg(vp, char *)) != NULL));
return vdorv;
}
static apr_table_entry_t **table_mergesort(apr_pool_t *pool,
apr_table_entry_t **values,
apr_size_t n)
{
/* Bottom-up mergesort, based on design in Sedgewick's "Algorithms
* in C," chapter 8
*/
apr_table_entry_t **values_tmp =
(apr_table_entry_t **)apr_palloc(pool, n * sizeof(apr_table_entry_t*));
apr_size_t i;
apr_size_t blocksize;
/* First pass: sort pairs of elements (blocksize=1) */
for (i = 0; i + 1 < n; i += 2) {
if (strcasecmp(values[i]->key, values[i + 1]->key) > 0) {
apr_table_entry_t *swap = values[i];
values[i] = values[i + 1];
values[i + 1] = swap;
}
}
/* Merge successively larger blocks */
blocksize = 2;
while (blocksize < n) {
apr_table_entry_t **dst = values_tmp;
apr_size_t next_start;
apr_table_entry_t **swap;
/* Merge consecutive pairs blocks of the next blocksize.
* Within a block, elements are in sorted order due to
* the previous iteration.
*/
for (next_start = 0; next_start + blocksize < n;
next_start += (blocksize + blocksize)) {
apr_size_t block1_start = next_start;
apr_size_t block2_start = block1_start + blocksize;
apr_size_t block1_end = block2_start;
apr_size_t block2_end = block2_start + blocksize;
if (block2_end > n) {
/* The last block may be smaller than blocksize */
block2_end = n;
}
for (;;) {
/* Merge the next two blocks:
* Pick the smaller of the next element from
* block 1 and the next element from block 2.
* Once either of the blocks is emptied, copy
* over all the remaining elements from the
* other block
*/
if (block1_start == block1_end) {
for (; block2_start < block2_end; block2_start++) {
*dst++ = values[block2_start];
}
break;
}
else if (block2_start == block2_end) {
for (; block1_start < block1_end; block1_start++) {
*dst++ = values[block1_start];
}
break;
}
if (strcasecmp(values[block1_start]->key,
values[block2_start]->key) > 0) {
*dst++ = values[block2_start++];
}
else {
*dst++ = values[block1_start++];
}
}
}
/* If n is not a multiple of 2*blocksize, some elements
* will be left over at the end of the array.
*/
for (i = dst - values_tmp; i < n; i++) {
values_tmp[i] = values[i];
}
/* The output array of this pass becomes the input
* array of the next pass, and vice versa
*/
swap = values_tmp;
values_tmp = values;
values = swap;
blocksize += blocksize;
}
return values;
}
APR_DECLARE(void) apr_table_compress(apr_table_t *t, unsigned flags)
{
apr_table_entry_t **sort_array;
apr_table_entry_t **sort_next;
apr_table_entry_t **sort_end;
apr_table_entry_t *table_next;
apr_table_entry_t **last;
int i;
int dups_found;
if (t->a.nelts <= 1) {
return;
}
/* Copy pointers to all the table elements into an
* array and sort to allow for easy detection of
* duplicate keys
*/
sort_array = (apr_table_entry_t **)
apr_palloc(t->a.pool, t->a.nelts * sizeof(apr_table_entry_t*));
sort_next = sort_array;
table_next = (apr_table_entry_t *)t->a.elts;
i = t->a.nelts;
do {
*sort_next++ = table_next++;
} while (--i);
/* Note: the merge is done with mergesort instead of quicksort
* because mergesort is a stable sort and runs in n*log(n)
* time regardless of its inputs (quicksort is quadratic in
* the worst case)
*/
sort_array = table_mergesort(t->a.pool, sort_array, t->a.nelts);
/* Process any duplicate keys */
dups_found = 0;
sort_next = sort_array;
sort_end = sort_array + t->a.nelts;
last = sort_next++;
while (sort_next < sort_end) {
if (((*sort_next)->key_checksum == (*last)->key_checksum) &&
!strcasecmp((*sort_next)->key, (*last)->key)) {
apr_table_entry_t **dup_last = sort_next + 1;
dups_found = 1;
while ((dup_last < sort_end) &&
((*dup_last)->key_checksum == (*last)->key_checksum) &&
!strcasecmp((*dup_last)->key, (*last)->key)) {
dup_last++;
}
dup_last--; /* Elements from last through dup_last, inclusive,
* all have the same key
*/
if (flags == APR_OVERLAP_TABLES_MERGE) {
apr_size_t len = 0;
apr_table_entry_t **next = last;
char *new_val;
char *val_dst;
do {
len += strlen((*next)->val);
len += 2; /* for ", " or trailing null */
} while (++next <= dup_last);
new_val = (char *)apr_palloc(t->a.pool, len);
val_dst = new_val;
next = last;
for (;;) {
strcpy(val_dst, (*next)->val);
val_dst += strlen((*next)->val);
next++;
if (next > dup_last) {
*val_dst = 0;
break;
}
else {
*val_dst++ = ',';
*val_dst++ = ' ';
}
}
(*last)->val = new_val;
}
else { /* overwrite */
(*last)->val = (*dup_last)->val;
}
do {
(*sort_next)->key = NULL;
} while (++sort_next <= dup_last);
}
else {
last = sort_next++;
}
}
/* Shift elements to the left to fill holes left by removing duplicates */
if (dups_found) {
apr_table_entry_t *src = (apr_table_entry_t *)t->a.elts;
apr_table_entry_t *dst = (apr_table_entry_t *)t->a.elts;
apr_table_entry_t *last_elt = src + t->a.nelts;
do {
if (src->key) {
*dst++ = *src;
}
} while (++src < last_elt);
t->a.nelts -= (int)(last_elt - dst);
}
table_reindex(t);
}
static void apr_table_cat(apr_table_t *t, const apr_table_t *s)
{
const int n = t->a.nelts;
register int idx;
apr_array_cat(&t->a,&s->a);
if (n == 0) {
memcpy(t->index_first,s->index_first,sizeof(int) * TABLE_HASH_SIZE);
memcpy(t->index_last, s->index_last, sizeof(int) * TABLE_HASH_SIZE);
t->index_initialized = s->index_initialized;
return;
}
for (idx = 0; idx < TABLE_HASH_SIZE; ++idx) {
if (TABLE_INDEX_IS_INITIALIZED(s, idx)) {
t->index_last[idx] = s->index_last[idx] + n;
if (!TABLE_INDEX_IS_INITIALIZED(t, idx)) {
t->index_first[idx] = s->index_first[idx] + n;
}
}
}
t->index_initialized |= s->index_initialized;
}
APR_DECLARE(void) apr_table_overlap(apr_table_t *a, const apr_table_t *b,
unsigned flags)
{
if (a->a.nelts + b->a.nelts == 0) {
return;
}
#if APR_POOL_DEBUG
/* Since the keys and values are not copied, it's required that
* b->a.pool has a lifetime at least as long as a->a.pool. */
if (!apr_pool_is_ancestor(b->a.pool, a->a.pool)) {
fprintf(stderr, "apr_table_overlap: b's pool is not an ancestor of a's\n");
abort();
}
#endif
apr_table_cat(a, b);
apr_table_compress(a, flags);
}
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