netsurf/content/fetchers/resource.c
John Mark Bell 308f549f78 Fix backend fetcher poll loops
svn path=/trunk/netsurf/; revision=11775
2011-02-23 22:41:17 +00:00

279 lines
6.7 KiB
C

/*
* Copyright 2011 Vincent Sanders <vince@netsurf-browser.org>
*
* This file is part of NetSurf.
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* resource: URL handling. Based on the data fetcher by Rob Kendrick */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <inttypes.h>
#include <string.h>
#include <strings.h>
#include <time.h>
#include <stdio.h>
#include <dirent.h>
#include <limits.h>
#include <stdarg.h>
#include "utils/config.h"
#include "content/dirlist.h"
#include "content/fetch.h"
#include "content/fetchers/resource.h"
#include "content/urldb.h"
#include "desktop/netsurf.h"
#include "desktop/options.h"
#include "utils/log.h"
#include "utils/messages.h"
#include "utils/url.h"
#include "utils/utils.h"
#include "utils/ring.h"
struct fetch_resource_context;
typedef bool (*fetch_resource_handler)(struct fetch_resource_context *);
/** Context for an resource fetch */
struct fetch_resource_context {
struct fetch_resource_context *r_next, *r_prev;
struct fetch *fetchh; /**< Handle for this fetch */
bool aborted; /**< Flag indicating fetch has been aborted */
bool locked; /**< Flag indicating entry is already entered */
char *url;
char *redirect_url; /**< The url the fetch redirects to */
fetch_resource_handler handler;
};
static struct fetch_resource_context *ring = NULL;
/** issue fetch callbacks with locking */
static inline bool fetch_resource_send_callback(fetch_msg msg,
struct fetch_resource_context *ctx, const void *data,
unsigned long size, fetch_error_code errorcode)
{
ctx->locked = true;
fetch_send_callback(msg, ctx->fetchh, data, size, errorcode);
ctx->locked = false;
return ctx->aborted;
}
static bool fetch_resource_send_header(struct fetch_resource_context *ctx,
const char *fmt, ...)
{
char header[64];
va_list ap;
va_start(ap, fmt);
vsnprintf(header, sizeof header, fmt, ap);
va_end(ap);
fetch_resource_send_callback(FETCH_HEADER, ctx, header, strlen(header),
FETCH_ERROR_NO_ERROR);
return ctx->aborted;
}
static bool fetch_resource_redirect_handler(struct fetch_resource_context *ctx)
{
/* content is going to return redirect */
fetch_set_http_code(ctx->fetchh, 302);
fetch_resource_send_callback(FETCH_REDIRECT, ctx, ctx->redirect_url, 0,
FETCH_ERROR_NO_ERROR);
return true;
}
static bool fetch_resource_notfound_handler(struct fetch_resource_context *ctx)
{
int code = 404;
char buffer[1024];
const char *title;
char key[8];
/* content is going to return error code */
fetch_set_http_code(ctx->fetchh, code);
/* content type */
if (fetch_resource_send_header(ctx, "Content-Type: text/html"))
goto fetch_resource_notfound_handler_aborted;
snprintf(key, sizeof key, "HTTP%03d", code);
title = messages_get(key);
snprintf(buffer, sizeof buffer, "<html><head><title>%s</title></head>"
"<body><h1>%s</h1>"
"<p>Error %d while fetching file %s</p></body></html>",
title, title, code, ctx->url);
if (fetch_resource_send_callback(FETCH_DATA, ctx, buffer, strlen(buffer),
FETCH_ERROR_NO_ERROR))
goto fetch_resource_notfound_handler_aborted;
fetch_resource_send_callback(FETCH_FINISHED, ctx, 0, 0,
FETCH_ERROR_NO_ERROR);
fetch_resource_notfound_handler_aborted:
return false;
}
/** callback to initialise the resource fetcher. */
static bool fetch_resource_initialise(const char *scheme)
{
return true;
}
/** callback to initialise the resource fetcher. */
static void fetch_resource_finalise(const char *scheme)
{
}
/** callback to set up a resource fetch context. */
static void *
fetch_resource_setup(struct fetch *fetchh,
const char *url,
bool only_2xx,
const char *post_urlenc,
const struct fetch_multipart_data *post_multipart,
const char **headers)
{
struct fetch_resource_context *ctx;
struct url_components urlcomp;
ctx = calloc(1, sizeof(*ctx));
if (ctx == NULL)
return NULL;
url_get_components(url, &urlcomp);
ctx->redirect_url = gui_find_resource(urlcomp.path);
if (ctx->redirect_url == NULL) {
ctx->handler = fetch_resource_notfound_handler;
} else {
ctx->handler = fetch_resource_redirect_handler;
}
ctx->url = strdup(url);
url_destroy_components(&urlcomp);
ctx->fetchh = fetchh;
RING_INSERT(ring, ctx);
return ctx;
}
/** callback to free a resource fetch */
static void fetch_resource_free(void *ctx)
{
struct fetch_resource_context *c = ctx;
free(c->redirect_url);
free(c->url);
RING_REMOVE(ring, c);
free(ctx);
}
/** callback to start a resource fetch */
static bool fetch_resource_start(void *ctx)
{
return true;
}
/** callback to abort a resource fetch */
static void fetch_resource_abort(void *ctx)
{
struct fetch_resource_context *c = ctx;
/* To avoid the poll loop having to deal with the fetch context
* disappearing from under it, we simply flag the abort here.
* The poll loop itself will perform the appropriate cleanup.
*/
c->aborted = true;
}
/** callback to poll for additional resource fetch contents */
static void fetch_resource_poll(const char *scheme)
{
struct fetch_resource_context *c, *next;
if (ring == NULL) return;
/* Iterate over ring, processing each pending fetch */
c = ring;
do {
/* Ignore fetches that have been flagged as locked.
* This allows safe re-entrant calls to this function.
* Re-entrancy can occur if, as a result of a callback,
* the interested party causes fetch_poll() to be called
* again.
*/
if (c->locked == true) {
next = c->r_next;
continue;
}
/* Only process non-aborted fetches */
if (c->aborted == false) {
/* resource fetches can be processed in one go */
c->handler(c);
}
/* Compute next fetch item at the last possible moment
* as processing this item may have added to the ring
*/
next = c->r_next;
fetch_remove_from_queues(c->fetchh);
fetch_free(c->fetchh);
/* Advance to next ring entry, exiting if we've reached
* the start of the ring or the ring has become empty
*/
} while ( (c = next) != ring && ring != NULL);
}
void fetch_resource_register(void)
{
fetch_add_fetcher("resource",
fetch_resource_initialise,
fetch_resource_setup,
fetch_resource_start,
fetch_resource_abort,
fetch_resource_free,
fetch_resource_poll,
fetch_resource_finalise);
}