root/main/streams/filter.c

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DEFINITIONS

This source file includes following definitions.
  1. php_get_stream_filters_hash_global
  2. _php_get_stream_filters_hash
  3. php_stream_filter_register_factory
  4. php_stream_filter_unregister_factory
  5. php_stream_filter_register_factory_volatile
  6. php_stream_bucket_new
  7. php_stream_bucket_make_writeable
  8. php_stream_bucket_split
  9. php_stream_bucket_delref
  10. php_stream_bucket_prepend
  11. php_stream_bucket_append
  12. php_stream_bucket_unlink
  13. php_stream_filter_create
  14. _php_stream_filter_alloc
  15. php_stream_filter_free
  16. _php_stream_filter_prepend
  17. _php_stream_filter_append
  18. _php_stream_filter_flush
  19. php_stream_filter_remove

/*
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2008 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Wez Furlong <wez@thebrainroom.com>                          |
   +----------------------------------------------------------------------+
 */

/* $Id: filter.c,v 1.17.2.3.2.11 2007/12/31 07:20:15 sebastian Exp $ */

#include "php.h"
#include "php_globals.h"
#include "php_network.h"
#include "php_open_temporary_file.h"
#include "ext/standard/file.h"
#include <stddef.h>
#include <fcntl.h>

#include "php_streams_int.h"

/* Global filter hash, copied to FG(stream_filters) on registration of volatile filter */
static HashTable stream_filters_hash;

/* Should only be used during core initialization */
PHPAPI HashTable *php_get_stream_filters_hash_global(void)
{
        return &stream_filters_hash;
}

/* Normal hash selection/retrieval call */
PHPAPI HashTable *_php_get_stream_filters_hash(TSRMLS_D)
{
        return (FG(stream_filters) ? FG(stream_filters) : &stream_filters_hash);
}

/* API for registering GLOBAL filters */
PHPAPI int php_stream_filter_register_factory(const char *filterpattern, php_stream_filter_factory *factory TSRMLS_DC)
{
        return zend_hash_add(&stream_filters_hash, (char*)filterpattern, strlen(filterpattern) + 1, factory, sizeof(*factory), NULL);
}

PHPAPI int php_stream_filter_unregister_factory(const char *filterpattern TSRMLS_DC)
{
        return zend_hash_del(&stream_filters_hash, (char*)filterpattern, strlen(filterpattern) + 1);
}

/* API for registering VOLATILE wrappers */
PHPAPI int php_stream_filter_register_factory_volatile(const char *filterpattern, php_stream_filter_factory *factory TSRMLS_DC)
{
        if (!FG(stream_filters)) {
                php_stream_filter_factory tmpfactory;

                ALLOC_HASHTABLE(FG(stream_filters));
                zend_hash_init(FG(stream_filters), zend_hash_num_elements(&stream_filters_hash), NULL, NULL, 1);
                zend_hash_copy(FG(stream_filters), &stream_filters_hash, NULL, &tmpfactory, sizeof(php_stream_filter_factory));
        }

        return zend_hash_add(FG(stream_filters), (char*)filterpattern, strlen(filterpattern) + 1, factory, sizeof(*factory), NULL);
}

/* Buckets */

PHPAPI php_stream_bucket *php_stream_bucket_new(php_stream *stream, char *buf, size_t buflen, int own_buf, int buf_persistent TSRMLS_DC)
{
        int is_persistent = php_stream_is_persistent(stream);
        php_stream_bucket *bucket;

        bucket = (php_stream_bucket*)pemalloc(sizeof(php_stream_bucket), is_persistent);

        if (bucket == NULL) {
                return NULL;
        }
        
        bucket->next = bucket->prev = NULL;

        if (is_persistent && !buf_persistent) {
                /* all data in a persistent bucket must also be persistent */
                bucket->buf = pemalloc(buflen, 1);
                
                if (bucket->buf == NULL) {
                        pefree(bucket, 1);
                        return NULL;
                }
                
                memcpy(bucket->buf, buf, buflen);
                bucket->buflen = buflen;
                bucket->own_buf = 1;
        } else {
                bucket->buf = buf;
                bucket->buflen = buflen;
                bucket->own_buf = own_buf;
        }
        bucket->is_persistent = is_persistent;
        bucket->refcount = 1;
        bucket->brigade = NULL;

        return bucket;
}

/* Given a bucket, returns a version of that bucket with a writeable buffer.
 * If the original bucket has a refcount of 1 and owns its buffer, then it
 * is returned unchanged.
 * Otherwise, a copy of the buffer is made.
 * In both cases, the original bucket is unlinked from its brigade.
 * If a copy is made, the original bucket is delref'd.
 * */
PHPAPI php_stream_bucket *php_stream_bucket_make_writeable(php_stream_bucket *bucket TSRMLS_DC)
{
        php_stream_bucket *retval;

        php_stream_bucket_unlink(bucket TSRMLS_CC);
        
        if (bucket->refcount == 1 && bucket->own_buf) {
                return bucket;
        }

        retval = (php_stream_bucket*)pemalloc(sizeof(php_stream_bucket), bucket->is_persistent);
        memcpy(retval, bucket, sizeof(*retval));

        retval->buf = pemalloc(retval->buflen, retval->is_persistent);
        memcpy(retval->buf, bucket->buf, retval->buflen);

        retval->refcount = 1;
        retval->own_buf = 1;

        php_stream_bucket_delref(bucket TSRMLS_CC);
        
        return retval;
}

PHPAPI int php_stream_bucket_split(php_stream_bucket *in, php_stream_bucket **left, php_stream_bucket **right, size_t length TSRMLS_DC)
{
        *left = (php_stream_bucket*)pecalloc(1, sizeof(php_stream_bucket), in->is_persistent);
        *right = (php_stream_bucket*)pecalloc(1, sizeof(php_stream_bucket), in->is_persistent);

        if (*left == NULL || *right == NULL) {
                goto exit_fail;
        }

        (*left)->buf = pemalloc(length, in->is_persistent);
        (*left)->buflen = length;
        memcpy((*left)->buf, in->buf, length);
        (*left)->refcount = 1;
        (*left)->own_buf = 1;
        (*left)->is_persistent = in->is_persistent;
        
        (*right)->buflen = in->buflen - length;
        (*right)->buf = pemalloc((*right)->buflen, in->is_persistent);
        memcpy((*right)->buf, in->buf + length, (*right)->buflen);
        (*right)->refcount = 1;
        (*right)->own_buf = 1;
        (*right)->is_persistent = in->is_persistent;
        
        return SUCCESS;
        
exit_fail:
        if (*right) {
                if ((*right)->buf) {
                        pefree((*right)->buf, in->is_persistent);
                }
                pefree(*right, in->is_persistent);
        }
        if (*left) {
                if ((*left)->buf) {
                        pefree((*left)->buf, in->is_persistent);
                }
                pefree(*left, in->is_persistent);
        }
        return FAILURE;
}

PHPAPI void php_stream_bucket_delref(php_stream_bucket *bucket TSRMLS_DC)
{
        if (--bucket->refcount == 0) {
                if (bucket->own_buf) {
                        pefree(bucket->buf, bucket->is_persistent);
                }
                pefree(bucket, bucket->is_persistent);
        }
}

PHPAPI void php_stream_bucket_prepend(php_stream_bucket_brigade *brigade, php_stream_bucket *bucket TSRMLS_DC)
{
        bucket->next = brigade->head;
        bucket->prev = NULL;

        if (brigade->head) {
                brigade->head->prev = bucket;
        } else {
                brigade->tail = bucket;
        }
        brigade->head = bucket;
        bucket->brigade = brigade;
}

PHPAPI void php_stream_bucket_append(php_stream_bucket_brigade *brigade, php_stream_bucket *bucket TSRMLS_DC)
{
        if (brigade->tail == bucket) {
                return;
        }

        bucket->prev = brigade->tail;
        bucket->next = NULL;

        if (brigade->tail) {
                brigade->tail->next = bucket;
        } else {
                brigade->head = bucket;
        }
        brigade->tail = bucket;
        bucket->brigade = brigade;
}

PHPAPI void php_stream_bucket_unlink(php_stream_bucket *bucket TSRMLS_DC)
{
        if (bucket->prev) {
                bucket->prev->next = bucket->next;
        } else if (bucket->brigade) {
                bucket->brigade->head = bucket->next;
        }
        if (bucket->next) {
                bucket->next->prev = bucket->prev;
        } else if (bucket->brigade) {
                bucket->brigade->tail = bucket->prev;
        }
        bucket->brigade = NULL;
        bucket->next = bucket->prev = NULL;
}
        







/* We allow very simple pattern matching for filter factories:
 * if "convert.charset.utf-8/sjis" is requested, we search first for an exact
 * match. If that fails, we try "convert.charset.*", then "convert.*"
 * This means that we don't need to clog up the hashtable with a zillion
 * charsets (for example) but still be able to provide them all as filters */
PHPAPI php_stream_filter *php_stream_filter_create(const char *filtername, zval *filterparams, int persistent TSRMLS_DC)
{
        HashTable *filter_hash = (FG(stream_filters) ? FG(stream_filters) : &stream_filters_hash);
        php_stream_filter_factory *factory = NULL;
        php_stream_filter *filter = NULL;
        int n;
        char *period;

        n = strlen(filtername);
        
        if (SUCCESS == zend_hash_find(filter_hash, (char*)filtername, n + 1, (void**)&factory)) {
                filter = factory->create_filter(filtername, filterparams, persistent TSRMLS_CC);
        } else if ((period = strrchr(filtername, '.'))) {
                /* try a wildcard */
                char *wildname;

                wildname = emalloc(n+3);
                memcpy(wildname, filtername, n+1);
                period = wildname + (period - filtername);
                while (period && !filter) {
                        *period = '\0';
                        strcat(wildname, ".*");
                        if (SUCCESS == zend_hash_find(filter_hash, wildname, strlen(wildname) + 1, (void**)&factory)) {
                                filter = factory->create_filter(filtername, filterparams, persistent TSRMLS_CC);
                        }

                        *period = '\0';
                        period = strrchr(wildname, '.');
                }
                efree(wildname);
        }

        if (filter == NULL) {
                /* TODO: these need correct docrefs */
                if (factory == NULL)
                        php_error_docref(NULL TSRMLS_CC, E_WARNING, "unable to locate filter \"%s\"", filtername);
                else
                        php_error_docref(NULL TSRMLS_CC, E_WARNING, "unable to create or locate filter \"%s\"", filtername);
        }
        
        return filter;
}

PHPAPI php_stream_filter *_php_stream_filter_alloc(php_stream_filter_ops *fops, void *abstract, int persistent STREAMS_DC TSRMLS_DC)
{
        php_stream_filter *filter;

        filter = (php_stream_filter*) pemalloc_rel_orig(sizeof(php_stream_filter), persistent);
        memset(filter, 0, sizeof(php_stream_filter));

        filter->fops = fops;
        filter->abstract = abstract;
        filter->is_persistent = persistent;
        
        return filter;
}

PHPAPI void php_stream_filter_free(php_stream_filter *filter TSRMLS_DC)
{
        if (filter->fops->dtor)
                filter->fops->dtor(filter TSRMLS_CC);
        pefree(filter, filter->is_persistent);
}

PHPAPI void _php_stream_filter_prepend(php_stream_filter_chain *chain, php_stream_filter *filter TSRMLS_DC)
{
        filter->next = chain->head;
        filter->prev = NULL;

        if (chain->head) {
                chain->head->prev = filter;
        } else {
                chain->tail = filter;
        }
        chain->head = filter;
        filter->chain = chain;
}

PHPAPI void _php_stream_filter_append(php_stream_filter_chain *chain, php_stream_filter *filter TSRMLS_DC)
{
        php_stream *stream = chain->stream;

        filter->prev = chain->tail;
        filter->next = NULL;
        if (chain->tail) {
                chain->tail->next = filter;
        } else {
                chain->head = filter;
        }
        chain->tail = filter;
        filter->chain = chain;

        if (&(stream->readfilters) == chain && (stream->writepos - stream->readpos) > 0) {
                /* Let's going ahead and wind anything in the buffer through this filter */
                php_stream_bucket_brigade brig_in = { NULL, NULL }, brig_out = { NULL, NULL };
                php_stream_bucket_brigade *brig_inp = &brig_in, *brig_outp = &brig_out;
                php_stream_filter_status_t status;
                php_stream_bucket *bucket;
                size_t consumed = 0;

                bucket = php_stream_bucket_new(stream, stream->readbuf + stream->readpos, stream->writepos - stream->readpos, 0, 0 TSRMLS_CC);
                php_stream_bucket_append(brig_inp, bucket TSRMLS_CC);
                status = filter->fops->filter(stream, filter, brig_inp, brig_outp, &consumed, PSFS_FLAG_NORMAL TSRMLS_CC);

                if (stream->readpos + consumed > (uint)stream->writepos || consumed < 0) {
                        /* No behaving filter should cause this. */
                        status = PSFS_ERR_FATAL;
                }

                switch (status) {
                        case PSFS_ERR_FATAL:
                                /* If this first cycle simply fails then there's something wrong with the filter.
                                   Pull the filter off the chain and leave the read buffer alone. */
                                if (chain->head == filter) {
                                        chain->head = NULL;
                                        chain->tail = NULL;
                                } else {
                                        filter->prev->next = NULL;
                                        chain->tail = filter->prev;
                                }
                                php_stream_bucket_unlink(bucket TSRMLS_CC);
                                php_stream_bucket_delref(bucket TSRMLS_CC);
                                php_error_docref(NULL TSRMLS_CC, E_WARNING, "Filter failed to process pre-buffered data.  Not adding to filterchain.");
                                break;
                        case PSFS_FEED_ME:
                                /* We don't actually need data yet,
                                   leave this filter in a feed me state until data is needed. 
                                   Reset stream's internal read buffer since the filter is "holding" it. */
                                stream->readpos = 0;
                                stream->writepos = 0;
                                break;
                        case PSFS_PASS_ON:
                                /* Put any filtered data onto the readbuffer stack.
                                   Previously read data has been at least partially consumed. */
                                stream->readpos += consumed;

                                if (stream->writepos == stream->readpos) {
                                        /* Entirely consumed */
                                        stream->writepos = 0;
                                        stream->readpos = 0;
                                }

                                while (brig_outp->head) {
                                        bucket = brig_outp->head;
                                        /* Grow buffer to hold this bucket if need be.
                                           TODO: See warning in main/stream/streams.c::php_stream_fill_read_buffer */
                                        if (stream->readbuflen - stream->writepos < bucket->buflen) {
                                                stream->readbuflen += bucket->buflen;
                                                stream->readbuf = perealloc(stream->readbuf, stream->readbuflen, stream->is_persistent);
                                        }
                                        memcpy(stream->readbuf + stream->writepos, bucket->buf, bucket->buflen);
                                        stream->writepos += bucket->buflen;

                                        php_stream_bucket_unlink(bucket TSRMLS_CC);
                                        php_stream_bucket_delref(bucket TSRMLS_CC);
                                }
                                break;
                }
        }

}

PHPAPI int _php_stream_filter_flush(php_stream_filter *filter, int finish TSRMLS_DC)
{
        php_stream_bucket_brigade brig_a = { NULL, NULL }, brig_b = { NULL, NULL }, *inp = &brig_a, *outp = &brig_b, *brig_temp;
        php_stream_bucket *bucket;
        php_stream_filter_chain *chain;
        php_stream_filter *current;
        php_stream *stream;
        size_t flushed_size = 0;
        long flags = (finish ? PSFS_FLAG_FLUSH_CLOSE : PSFS_FLAG_FLUSH_INC);

        if (!filter->chain || !filter->chain->stream) {
                /* Filter is not attached to a chain, or chain is somehow not part of a stream */
                return FAILURE;
        }

        chain = filter->chain;
        stream = chain->stream;

        for(current = filter; current; current = current->next) {
                php_stream_filter_status_t status;

                status = filter->fops->filter(stream, filter, inp, outp, NULL, flags TSRMLS_CC);
                if (status == PSFS_FEED_ME) {
                        /* We've flushed the data far enough */
                        return SUCCESS;
                }
                if (status == PSFS_ERR_FATAL) {
                        return FAILURE;
                }
                /* Otherwise we have data available to PASS_ON
                        Swap the brigades and continue */
                brig_temp = inp;
                inp = outp;
                outp = brig_temp;
                outp->head = NULL;
                outp->tail = NULL;

                flags = PSFS_FLAG_NORMAL;
        }

        /* Last filter returned data via PSFS_PASS_ON
                Do something with it */

        for(bucket = inp->head; bucket; bucket = bucket->next) {
                flushed_size += bucket->buflen;
        }

        if (flushed_size == 0) {
                /* Unlikely, but possible */
                return SUCCESS;
        }

        if (chain == &(stream->readfilters)) {
                /* Dump any newly flushed data to the read buffer */
                if (stream->readpos > 0) {
                        /* Back the buffer up */
                        memcpy(stream->readbuf, stream->readbuf + stream->readpos, stream->writepos - stream->readpos);
                        stream->readpos = 0;
                        stream->writepos -= stream->readpos;
                }
                if (flushed_size > (stream->readbuflen - stream->writepos)) {
                        /* Grow the buffer */
                        stream->readbuf = perealloc(stream->readbuf, stream->writepos + flushed_size + stream->chunk_size, stream->is_persistent);
                }
                while ((bucket = inp->head)) {
                        memcpy(stream->readbuf + stream->writepos, bucket->buf, bucket->buflen);
                        stream->writepos += bucket->buflen;
                        php_stream_bucket_unlink(bucket TSRMLS_CC);
                        php_stream_bucket_delref(bucket TSRMLS_CC);
                }
        } else if (chain == &(stream->writefilters)) {
                /* Send flushed data to the stream */
                while ((bucket = inp->head)) {
                        stream->ops->write(stream, bucket->buf, bucket->buflen TSRMLS_CC);
                        php_stream_bucket_unlink(bucket TSRMLS_CC);
                        php_stream_bucket_delref(bucket TSRMLS_CC);
                }
        }

        return SUCCESS;
}

PHPAPI php_stream_filter *php_stream_filter_remove(php_stream_filter *filter, int call_dtor TSRMLS_DC)
{
        if (filter->prev) {
                filter->prev->next = filter->next;
        } else {
                filter->chain->head = filter->next;
        }
        if (filter->next) {
                filter->next->prev = filter->prev;
        } else {
                filter->chain->tail = filter->prev;
        }

        if (filter->rsrc_id > 0) {
                zend_list_delete(filter->rsrc_id);
        }

        if (call_dtor) {
                php_stream_filter_free(filter TSRMLS_CC);
                return NULL;
        }
        return filter;
}

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4
 */

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