buckets/ap_buckets_pipe.c

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#include "httpd.h"
#include "ap_buckets.h"
#include <stdlib.h>

/* XXX: We should obey the block flag */
static apr_status_t pipe_read(ap_bucket *a, const char **str,
			      apr_size_t *len, ap_read_type block)
{
    apr_file_t *p = a->data;
    ap_bucket *b;
    char *buf;
    apr_status_t rv;
    apr_interval_time_t timeout;

    if (block == AP_NONBLOCK_READ) {
        apr_get_pipe_timeout(p, &timeout);
        apr_set_pipe_timeout(p, 0);
    }

    buf = malloc(IOBUFSIZE); /* XXX: check for failure? */
    *str = buf;
    *len = IOBUFSIZE;
    rv = apr_read(p, buf, len);

    if (block == AP_NONBLOCK_READ) {
        apr_set_pipe_timeout(p, timeout);
    }

    if (rv != APR_SUCCESS && rv != APR_EOF) {
        *str = NULL;
	free(buf);
        return rv;
    }
    /*
     * Change the current bucket to refer to what we read,
     * even if we read nothing because we hit EOF.
     */
    ap_bucket_make_heap(a, buf, *len, 0, NULL);  /* XXX: check for failure? */
    /*
     * If there's more to read we have to keep the rest of the pipe
     * for later.  Otherwise, we'll close the pipe.
     * XXX: Note that more complicated bucket types that 
     * refer to data not in memory and must therefore have a read()
     * function similar to this one should be wary of copying this
     * code because if they have a destroy function they probably
     * want to migrate the bucket's subordinate structure from the
     * old bucket to a raw new one and adjust it as appropriate,
     * rather than destroying the old one and creating a completely
     * new bucket.
     */
    if (*len > 0) {
        b = ap_bucket_create_pipe(p);
	AP_BUCKET_INSERT_AFTER(a, b);
    }
    else {
        apr_close(p);
    }
    return APR_SUCCESS;
}

AP_DECLARE(ap_bucket *) ap_bucket_make_pipe(ap_bucket *b, apr_file_t *p)
{
    /*
     * A pipe is closed when the end is reached in pipe_read().  If the
     * pipe isn't read to the end (e.g., error path), the pipe will be
     * closed when its pool goes away.
     *
     * Note that typically the pipe is allocated from the request pool
     * so it will disappear when the request is finished. However the
     * core filter may decide to set aside the tail end of a CGI
     * response if the connection is pipelined. This turns out not to
     * be a problem because the core will have read to the end of the
     * stream so the bucket(s) that it sets aside will be the heap
     * buckets created by pipe_read() above.
     */
    b->type     = &ap_pipe_type;
    b->length   = -1;
    b->data     = p;

    return b;
}

AP_DECLARE(ap_bucket *) ap_bucket_create_pipe(apr_file_t *p)
{
    ap_bucket_do_create(ap_bucket_make_pipe(b, p));
}

const ap_bucket_type ap_pipe_type = {
    "PIPE", 4,
    ap_bucket_destroy_notimpl,
    pipe_read,
    ap_bucket_setaside_notimpl,
    ap_bucket_split_notimpl
};