Viewing file:  apr_tables.h (16.74 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2003 The Apache Software Foundation. All rights
* reserved.
*
* 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. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
* ITS 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
#ifndef APR_TABLES_H
#define APR_TABLES_H
/**
* @file apr_tables.h
* @brief APR Table library
*/
#include "apr.h"
#include "apr_pools.h"
#if APR_HAVE_STDARG_H
#include <stdarg.h> /* for va_list */
#endif
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @defgroup apr_tables Table and Array Functions
* @ingroup APR
* Tables are used to store entirely opaque structures
* for applications, while Arrays are usually used to
* deal with string lists.
* @{
*/
/** the table abstract data type */
typedef struct apr_table_t apr_table_t;
/** @see apr_array_header_t */
typedef struct apr_array_header_t apr_array_header_t;
/** An opaque array type */
struct apr_array_header_t {
/** The pool the array is allocated out of */
apr_pool_t *pool;
/** The amount of memory allocated for each element of the array */
int elt_size;
/** The number of active elements in the array */
int nelts;
/** The number of elements allocated in the array */
int nalloc;
/** The elements in the array */
char *elts;
};
/**
* The (opaque) structure for string-content tables.
*/
typedef struct apr_table_entry_t apr_table_entry_t;
/** The type for each entry in a string-content table */
struct apr_table_entry_t {
/** The key for the current table entry */
char *key; /* maybe NULL in future;
* check when iterating thru table_elts
*/
/** The value for the current table entry */
char *val;
/** A checksum for the key, for use by the apr_table internals */
apr_uint32_t key_checksum;
};
/**
* Get the elements from a table
* @param t The table
* @return An array containing the contents of the table
*/
APR_DECLARE(const apr_array_header_t *) apr_table_elts(const apr_table_t *t);
/**
* Determine if the table is empty
* @param t The table to check
* @return True if empty, False otherwise
*/
APR_DECLARE(int) apr_is_empty_table(const apr_table_t *t);
/**
* Determine if the array is empty
* @param a The array to check
* @return True if empty, False otherwise
*/
APR_DECLARE(int) apr_is_empty_array(const apr_array_header_t *a);
/**
* Create an array
* @param p The pool to allocate the memory out of
* @param nelts the number of elements in the initial array
* @param elt_size The size of each element in the array.
* @return The new array
*/
APR_DECLARE(apr_array_header_t *) apr_array_make(apr_pool_t *p,
int nelts, int elt_size);
/**
* Add a new element to an array
* @param arr The array to add an element to.
* @return Location for the new element in the array.
* @remark If there are no free spots in the array, then this function will
* allocate new space for the new element.
*/
APR_DECLARE(void *) apr_array_push(apr_array_header_t *arr);
/**
* Remove an element from an array
* @param arr The array to remove an element from.
* @return Location of the element in the array.
* @remark If there are no elements in the array, NULL is returned.
*/
APR_DECLARE(void *) apr_array_pop(apr_array_header_t *arr);
/**
* Concatenate two arrays together
* @param dst The destination array, and the one to go first in the combined
* array
* @param src The source array to add to the destination array
*/
APR_DECLARE(void) apr_array_cat(apr_array_header_t *dst,
const apr_array_header_t *src);
/**
* Copy the entire array
* @param p The pool to allocate the copy of the array out of
* @param arr The array to copy
* @return An exact copy of the array passed in
* @remark The alternate apr_array_copy_hdr copies only the header, and arranges
* for the elements to be copied if (and only if) the code subsequently
* does a push or arraycat.
*/
APR_DECLARE(apr_array_header_t *) apr_array_copy(apr_pool_t *p,
const apr_array_header_t *arr);
/**
* Copy the headers of the array, and arrange for the elements to be copied if
* and only if the code subsequently does a push or arraycat.
* @param p The pool to allocate the copy of the array out of
* @param arr The array to copy
* @return An exact copy of the array passed in
* @remark The alternate apr_array_copy copies the *entire* array.
*/
APR_DECLARE(apr_array_header_t *) apr_array_copy_hdr(apr_pool_t *p,
const apr_array_header_t *arr);
/**
* Append one array to the end of another, creating a new array in the process.
* @param p The pool to allocate the new array out of
* @param first The array to put first in the new array.
* @param second The array to put second in the new array.
* @return A new array containing the data from the two arrays passed in.
*/
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);
/**
* 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.
* @param p The pool to allocate the string out of
* @param arr The array to generate the string from
* @param sep The separator to use
* @return A string containing all of the data in the array.
*/
APR_DECLARE(char *) apr_array_pstrcat(apr_pool_t *p,
const apr_array_header_t *arr,
const char sep);
/**
* Make a new table
* @param p The pool to allocate the pool out of
* @param nelts The number of elements in the initial table.
* @return The new table.
* @warning This table can only store text data
*/
APR_DECLARE(apr_table_t *) apr_table_make(apr_pool_t *p, int nelts);
/**
* Create a new table and copy another table into it
* @param p The pool to allocate the new table out of
* @param t The table to copy
* @return A copy of the table passed in
*/
APR_DECLARE(apr_table_t *) apr_table_copy(apr_pool_t *p,
const apr_table_t *t);
/**
* Delete all of the elements from a table
* @param t The table to clear
*/
APR_DECLARE(void) apr_table_clear(apr_table_t *t);
/**
* Get the value associated with a given key from the table. After this call,
* The data is still in the table
* @param t The table to search for the key
* @param key The key to search for
* @return The value associated with the key
*/
APR_DECLARE(const char *) apr_table_get(const apr_table_t *t, const char *key);
/**
* Add a key/value pair to a table, if another element already exists with the
* same key, this will over-write the old data.
* @param t The table to add the data to.
* @param key The key fo use
* @param val The value to add
* @remark When adding data, this function makes a copy of both the key and the
* value.
*/
APR_DECLARE(void) apr_table_set(apr_table_t *t, const char *key,
const char *val);
/**
* Add a key/value pair to a table, if another element already exists with the
* same key, this will over-write the old data.
* @param t The table to add the data to.
* @param key The key to use
* @param val The value to add
* @warning When adding data, this function does not make a copy of the key or
* the value, so care should be taken to ensure that the values will
* not change after they have been added..
*/
APR_DECLARE(void) apr_table_setn(apr_table_t *t, const char *key,
const char *val);
/**
* Remove data from the table
* @param t The table to remove data from
* @param key The key of the data being removed
*/
APR_DECLARE(void) apr_table_unset(apr_table_t *t, const char *key);
/**
* Add data to a table by merging the value with data that has already been
* stored
* @param t The table to search for the data
* @param key The key to merge data for
* @param val The data to add
* @remark If the key is not found, then this function acts like apr_table_add
*/
APR_DECLARE(void) apr_table_merge(apr_table_t *t, const char *key,
const char *val);
/**
* Add data to a table by merging the value with data that has already been
* stored
* @param t The table to search for the data
* @param key The key to merge data for
* @param val The data to add
* @remark If the key is not found, then this function acts like apr_table_addn
*/
APR_DECLARE(void) apr_table_mergen(apr_table_t *t, const char *key,
const char *val);
/**
* Add data to a table, regardless of whether there is another element with the
* same key.
* @param t The table to add to
* @param key The key to use
* @param val The value to add.
* @remark When adding data, this function makes a copy of both the key and the
* value.
*/
APR_DECLARE(void) apr_table_add(apr_table_t *t, const char *key,
const char *val);
/**
* Add data to a table, regardless of whether there is another element with the
* same key.
* @param t The table to add to
* @param key The key to use
* @param val The value to add.
* @remark When adding data, this function does not make a copy of the key or the
* value, so care should be taken to ensure that the values will not
* change after they have been added..
*/
APR_DECLARE(void) apr_table_addn(apr_table_t *t, const char *key,
const char *val);
/**
* Merge two tables into one new table
* @param p The pool to use for the new table
* @param overlay The first table to put in the new table
* @param base The table to add at the end of the new table
* @return A new table containing all of the data from the two passed in
*/
APR_DECLARE(apr_table_t *) apr_table_overlay(apr_pool_t *p,
const apr_table_t *overlay,
const apr_table_t *base);
/**
* Declaration prototype for the iterator callback function of apr_table_do()
* and apr_table_vdo().
* @param rec The data passed as the first argument to apr_table_[v]do()
* @param key The key from this iteration of the table
* @param value The value from this iteration of the table
* @remark Iteration continues while this callback function returns non-zero.
* To export the callback function for apr_table_[v]do() it must be declared
* in the _NONSTD convention.
*/
typedef int (apr_table_do_callback_fn_t)(void *rec, const char *key,
const char *value);
/**
* Iterate over a table running the provided function once for every
* element in the table. If there is data passed in as a vararg, then the
* function is only run on those elements whose key matches something in
* the vararg. If the vararg is NULL, then every element is run through the
* function. Iteration continues while the function returns non-zero.
* @param comp The function to run
* @param rec The data to pass as the first argument to the function
* @param t The table to iterate over
* @param ... The vararg. If this is NULL, then all elements in the table are
* run through the function, otherwise only those whose key matches
* are run.
* @return FALSE if one of the comp() iterations returned zero; TRUE if all
* iterations returned non-zero
* @see apr_table_do_callback_fn_t
*/
APR_DECLARE_NONSTD(int) apr_table_do(apr_table_do_callback_fn_t *comp,
void *rec, const apr_table_t *t, ...);
/**
* Iterate over a table running the provided function once for every
* element in the table. If there is data passed in as a vararg, then the
* function is only run on those element's whose key matches something in
* the vararg. If the vararg is NULL, then every element is run through the
* function. Iteration continues while the function returns non-zero.
* @param comp The function to run
* @param rec The data to pass as the first argument to the function
* @param t The table to iterate over
* @param vp The vararg table. If this is NULL, then all elements in the
* table are run through the function, otherwise only those
* whose key matches are run.
* @return FALSE if one of the comp() iterations returned zero; TRUE if all
* iterations returned non-zero
* @see apr_table_do_callback_fn_t
*/
APR_DECLARE(int) apr_table_vdo(apr_table_do_callback_fn_t *comp,
void *rec, const apr_table_t *t, va_list vp);
/** flag for overlap to use apr_table_setn */
#define APR_OVERLAP_TABLES_SET (0)
/** flag for overlap to use apr_table_mergen */
#define APR_OVERLAP_TABLES_MERGE (1)
/**
* For each element in table b, either use setn or mergen to add the data
* to table a. Which method is used is determined by the flags passed in.
* @param a The table to add the data to.
* @param b The table to iterate over, adding its data to table a
* @param flags How to add the table to table a. One of:
* APR_OVERLAP_TABLES_SET Use apr_table_setn
* APR_OVERLAP_TABLES_MERGE Use apr_table_mergen
* @remark This function is highly optimized, and uses less memory and CPU cycles
* than a function that just loops through table b calling other functions.
*/
/**
*<PRE>
* Conceptually, apr_table_overlap does this:
*
* apr_array_header_t *barr = apr_table_elts(b);
* apr_table_entry_t *belt = (apr_table_entry_t *)barr->elts;
* int i;
*
* for (i = 0; i < barr->nelts; ++i) {
* if (flags & APR_OVERLAP_TABLES_MERGE) {
* apr_table_mergen(a, belt[i].key, belt[i].val);
* }
* else {
* apr_table_setn(a, belt[i].key, belt[i].val);
* }
* }
*
* Except that it is more efficient (less space and cpu-time) especially
* when b has many elements.
*
* Notice the assumptions on the keys and values in b -- they must be
* in an ancestor of a's pool. In practice b and a are usually from
* the same pool.
* </PRE>
*/
APR_DECLARE(void) apr_table_overlap(apr_table_t *a, const apr_table_t *b,
unsigned flags);
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* ! APR_TABLES_H */
|