netsurf/content/hlcache.c

700 lines
18 KiB
C

/*
* Copyright 2009 John-Mark Bell <jmb@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* 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/>.
*/
/** \file
* High-level resource cache (implementation)
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "content/content.h"
#include "content/hlcache.h"
#include "utils/http.h"
#include "utils/log.h"
#include "utils/messages.h"
#include "utils/ring.h"
#include "utils/url.h"
#include "utils/utils.h"
typedef struct hlcache_entry hlcache_entry;
typedef struct hlcache_retrieval_ctx hlcache_retrieval_ctx;
/** High-level cache retrieval context */
struct hlcache_retrieval_ctx {
struct hlcache_retrieval_ctx *r_prev; /**< Previous retrieval context in the ring */
struct hlcache_retrieval_ctx *r_next; /**< Next retrieval context in the ring */
llcache_handle *llcache; /**< Low-level cache handle */
hlcache_handle *handle; /**< High-level handle for object */
uint32_t flags; /**< Retrieval flags */
const content_type *accepted_types; /**< Accepted types, or NULL */
hlcache_child_context child; /**< Child context */
};
/** High-level cache handle */
struct hlcache_handle {
hlcache_entry *entry; /**< Pointer to cache entry */
hlcache_handle_callback cb; /**< Client callback */
void *pw; /**< Client data */
};
/** Entry in high-level cache */
struct hlcache_entry {
struct content *content; /**< Pointer to associated content */
hlcache_entry *next; /**< Next sibling */
hlcache_entry *prev; /**< Previous sibling */
};
/** List of cached content objects */
static hlcache_entry *hlcache_content_list;
/** Ring of retrieval contexts */
static hlcache_retrieval_ctx *hlcache_retrieval_ctx_ring;
static void hlcache_clean(void);
static nserror hlcache_llcache_callback(llcache_handle *handle,
const llcache_event *event, void *pw);
static bool hlcache_type_is_acceptable(llcache_handle *llcache,
const content_type *accepted_types,
content_type *computed_type);
static nserror hlcache_find_content(hlcache_retrieval_ctx *ctx);
static void hlcache_content_callback(struct content *c,
content_msg msg, union content_msg_data data, void *pw);
/******************************************************************************
* Public API *
******************************************************************************/
/* See hlcache.h for documentation */
void hlcache_finalise(void)
{
uint32_t num_contents, prev_contents;
hlcache_entry *entry;
hlcache_retrieval_ctx *ctx, *next;
/* Obtain initial count of contents remaining */
for (num_contents = 0, entry = hlcache_content_list;
entry != NULL; entry = entry->next) {
num_contents++;
}
LOG(("%d contents to before cache drain", num_contents));
/* Drain cache */
do {
prev_contents = num_contents;
hlcache_clean();
for (num_contents = 0, entry = hlcache_content_list;
entry != NULL; entry = entry->next) {
num_contents++;
}
} while (num_contents > 0 && num_contents != prev_contents);
LOG(("%d contents remaining:", num_contents));
for (entry = hlcache_content_list; entry != NULL; entry = entry->next) {
hlcache_handle entry_handle = { entry, NULL, NULL };
if (entry->content != NULL) {
LOG((" %p : %s (%d users)", entry,
content_get_url(&entry_handle), content_count_users(entry->content)));
} else {
LOG((" %p", entry));
}
}
/* Clean up retrieval contexts */
if (hlcache_retrieval_ctx_ring != NULL) {
ctx = hlcache_retrieval_ctx_ring;
do {
next = ctx->r_next;
if (ctx->llcache != NULL)
llcache_handle_release(ctx->llcache);
if (ctx->handle != NULL)
free(ctx->handle);
if (ctx->child.charset != NULL)
free((char *) ctx->child.charset);
free(ctx);
ctx = next;
} while (ctx != hlcache_retrieval_ctx_ring);
hlcache_retrieval_ctx_ring = NULL;
}
}
/* See hlcache.h for documentation */
nserror hlcache_poll(void)
{
static uint32_t last_clean_time;
uint32_t now;
llcache_poll();
/* Only attempt to clean the cache every 5 seconds */
#define HLCACHE_CLEAN_INTERVAL_CS (500)
now = wallclock();
if (now > last_clean_time + HLCACHE_CLEAN_INTERVAL_CS) {
/* Give the cache a clean */
hlcache_clean();
last_clean_time = now;
}
#undef HLCACHE_CLEAN_INTERVAL_CS
return NSERROR_OK;
}
/* See hlcache.h for documentation */
nserror hlcache_handle_retrieve(const char *url, uint32_t flags,
const char *referer, llcache_post_data *post,
hlcache_handle_callback cb, void *pw,
hlcache_child_context *child,
const content_type *accepted_types, hlcache_handle **result)
{
hlcache_retrieval_ctx *ctx;
nserror error;
assert(cb != NULL);
ctx = calloc(1, sizeof(hlcache_retrieval_ctx));
if (ctx == NULL)
return NSERROR_NOMEM;
ctx->handle = calloc(1, sizeof(hlcache_handle));
if (ctx->handle == NULL) {
free(ctx);
return NSERROR_NOMEM;
}
if (child != NULL) {
if (child->charset != NULL) {
ctx->child.charset = strdup(child->charset);
if (ctx->child.charset == NULL) {
free(ctx->handle);
free(ctx);
return NSERROR_NOMEM;
}
}
ctx->child.quirks = child->quirks;
}
ctx->flags = flags;
ctx->accepted_types = accepted_types;
ctx->handle->cb = cb;
ctx->handle->pw = pw;
error = llcache_handle_retrieve(url, flags, referer, post,
hlcache_llcache_callback, ctx,
&ctx->llcache);
if (error != NSERROR_OK) {
free((char *) ctx->child.charset);
free(ctx->handle);
free(ctx);
return error;
}
RING_INSERT(hlcache_retrieval_ctx_ring, ctx);
*result = ctx->handle;
return NSERROR_OK;
}
/* See hlcache.h for documentation */
nserror hlcache_handle_release(hlcache_handle *handle)
{
if (handle->entry != NULL) {
content_remove_user(handle->entry->content,
hlcache_content_callback, handle);
} else {
RING_ITERATE_START(struct hlcache_retrieval_ctx,
hlcache_retrieval_ctx_ring,
ictx) {
if (ictx->handle == handle) {
/* This is the nascent context for us,
* so abort the fetch */
llcache_handle_abort(ictx->llcache);
llcache_handle_release(ictx->llcache);
/* Remove us from the ring */
RING_REMOVE(hlcache_retrieval_ctx_ring, ictx);
/* Throw us away */
free((char *) ictx->child.charset);
free(ictx);
/* And stop */
RING_ITERATE_STOP(hlcache_retrieval_ctx_ring,
ictx);
}
} RING_ITERATE_END(hlcache_retrieval_ctx_ring, ictx);
}
handle->cb = NULL;
handle->pw = NULL;
free(handle);
return NSERROR_OK;
}
/* See hlcache.h for documentation */
struct content *hlcache_handle_get_content(const hlcache_handle *handle)
{
assert(handle != NULL);
if (handle->entry != NULL)
return handle->entry->content;
return NULL;
}
/* See hlcache.h for documentation */
nserror hlcache_handle_abort(hlcache_handle *handle)
{
struct hlcache_entry *entry = handle->entry;
struct content *c;
if (entry == NULL) {
/* This handle is not yet associated with a cache entry.
* The implication is that the fetch for the handle has
* not progressed to the point where the entry can be
* created. */
RING_ITERATE_START(struct hlcache_retrieval_ctx,
hlcache_retrieval_ctx_ring,
ictx) {
if (ictx->handle == handle) {
/* This is the nascent context for us,
* so abort the fetch */
llcache_handle_abort(ictx->llcache);
llcache_handle_release(ictx->llcache);
/* Remove us from the ring */
RING_REMOVE(hlcache_retrieval_ctx_ring, ictx);
/* Throw us away */
free((char *) ictx->child.charset);
free(ictx);
/* And stop */
RING_ITERATE_STOP(hlcache_retrieval_ctx_ring,
ictx);
}
} RING_ITERATE_END(hlcache_retrieval_ctx_ring, ictx);
return NSERROR_OK;
}
c = entry->content;
if (content_count_users(c) > 1) {
/* We are not the only user of 'c' so clone it. */
struct content *clone = content_clone(c);
if (clone == NULL)
return NSERROR_NOMEM;
entry = calloc(sizeof(struct hlcache_entry), 1);
if (entry == NULL) {
content_destroy(clone);
return NSERROR_NOMEM;
}
if (content_add_user(clone,
hlcache_content_callback, handle) == false) {
content_destroy(clone);
free(entry);
return NSERROR_NOMEM;
}
content_remove_user(c, hlcache_content_callback, handle);
entry->content = clone;
handle->entry = entry;
entry->prev = NULL;
entry->next = hlcache_content_list;
if (hlcache_content_list != NULL)
hlcache_content_list->prev = entry;
hlcache_content_list = entry;
c = clone;
}
return content_abort(c);
}
/* See hlcache.h for documentation */
nserror hlcache_handle_replace_callback(hlcache_handle *handle,
hlcache_handle_callback cb, void *pw)
{
handle->cb = cb;
handle->pw = pw;
return NSERROR_OK;
}
/******************************************************************************
* High-level cache internals *
******************************************************************************/
/**
* Attempt to clean the cache
*/
void hlcache_clean(void)
{
hlcache_entry *entry, *next;
for (entry = hlcache_content_list; entry != NULL; entry = next) {
next = entry->next;
if (entry->content == NULL)
continue;
if (content_count_users(entry->content) != 0)
continue;
/** \todo This is over-zealous: all unused contents
* will be immediately destroyed. Ideally, we want to
* purge all unused contents that are using stale
* source data, and enough fresh contents such that
* the cache fits in the configured cache size limit.
*/
/* Remove entry from cache */
if (entry->prev == NULL)
hlcache_content_list = entry->next;
else
entry->prev->next = entry->next;
if (entry->next != NULL)
entry->next->prev = entry->prev;
/* Destroy content */
content_destroy(entry->content);
/* Destroy entry */
free(entry);
}
}
/**
* Handler for low-level cache events
*
* \param handle Handle for which event is issued
* \param event Event data
* \param pw Pointer to client-specific data
* \return NSERROR_OK on success, appropriate error otherwise
*/
nserror hlcache_llcache_callback(llcache_handle *handle,
const llcache_event *event, void *pw)
{
hlcache_retrieval_ctx *ctx = pw;
nserror error;
assert(ctx->llcache == handle);
switch (event->type) {
case LLCACHE_EVENT_HAD_HEADERS:
{
content_type type = CONTENT_UNKNOWN;
/* Unlink the context to prevent recursion */
RING_REMOVE(hlcache_retrieval_ctx_ring, ctx);
if (hlcache_type_is_acceptable(handle,
ctx->accepted_types, &type)) {
error = hlcache_find_content(ctx);
if (error != NSERROR_OK) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_ERROR;
hlevent.data.error = messages_get("MiscError");
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
llcache_handle_abort(handle);
llcache_handle_release(handle);
free((char *) ctx->child.charset);
free(ctx);
return error;
}
} else if (type == CONTENT_OTHER &&
ctx->flags & HLCACHE_RETRIEVE_MAY_DOWNLOAD) {
/* Unknown type, and we can download, so convert */
llcache_handle_force_stream(handle);
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_DOWNLOAD;
hlevent.data.download = handle;
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
}
} else {
/* Unacceptable type: abort fetch and report error */
llcache_handle_abort(handle);
llcache_handle_release(handle);
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_ERROR;
hlevent.data.error = messages_get("BadType");
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
}
}
/* No longer require retrieval context */
free((char *) ctx->child.charset);
free(ctx);
}
break;
case LLCACHE_EVENT_HAD_DATA:
/* fall through */
case LLCACHE_EVENT_DONE:
/* should never happen: the handler must be changed */
assert(0 && "Unexpected llcache event");
break;
case LLCACHE_EVENT_ERROR:
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_ERROR;
hlevent.data.error = event->data.msg;
ctx->handle->cb(ctx->handle, &hlevent, ctx->handle->pw);
}
break;
case LLCACHE_EVENT_PROGRESS:
break;
}
return NSERROR_OK;
}
/**
* Determine if the type of a low-level cache object is acceptable
*
* \param llcache Low-level cache object to consider
* \param accepted_types Array of acceptable types, or NULL for any
* \param computed_type Pointer to location to receive computed type of object
* \return True if the type is acceptable, false otherwise
*/
bool hlcache_type_is_acceptable(llcache_handle *llcache,
const content_type *accepted_types, content_type *computed_type)
{
const char *content_type_header;
char *mime_type;
http_parameter *params;
content_type type;
nserror error;
bool acceptable;
content_type_header =
llcache_handle_get_header(llcache, "Content-Type");
if (content_type_header == NULL)
content_type_header = "text/plain";
error = http_parse_content_type(content_type_header, &mime_type,
&params);
if (error != NSERROR_OK)
return false;
type = content_lookup(mime_type);
free(mime_type);
http_parameter_list_destroy(params);
if (accepted_types == NULL) {
acceptable = type != CONTENT_OTHER;
} else {
while (*accepted_types != CONTENT_UNKNOWN) {
if (*accepted_types == type)
break;
accepted_types++;
}
acceptable = *accepted_types == type;
}
*computed_type = type;
return acceptable;
}
/**
* Find a content for the high-level cache handle
*
* \param ctx High-level cache retrieval context
* \return NSERROR_OK on success, appropriate error otherwise
*
* \pre handle::state == HLCACHE_HANDLE_NEW
* \pre Headers must have been received for associated low-level handle
* \post Low-level handle is either released, or associated with new content
* \post High-level handle is registered with content
*/
nserror hlcache_find_content(hlcache_retrieval_ctx *ctx)
{
hlcache_entry *entry;
hlcache_event event;
/* Search list of cached contents for a suitable one */
for (entry = hlcache_content_list; entry != NULL; entry = entry->next) {
hlcache_handle entry_handle = { entry, NULL, NULL };
const llcache_handle *entry_llcache;
if (entry->content == NULL)
continue;
/* Ignore contents in the error state */
if (content_get_status(&entry_handle) == CONTENT_STATUS_ERROR)
continue;
/* Ensure that content is shareable */
if (content_is_shareable(entry->content) == false)
continue;
/* Ensure that quirks mode is acceptable */
if (content_matches_quirks(entry->content,
ctx->child.quirks) == false)
continue;
/* Ensure that content uses same low-level object as
* low-level handle */
entry_llcache = content_get_llcache_handle(entry->content);
if (llcache_handle_references_same_object(entry_llcache,
ctx->llcache))
break;
}
if (entry == NULL) {
/* No existing entry, so need to create one */
entry = malloc(sizeof(hlcache_entry));
if (entry == NULL)
return NSERROR_NOMEM;
/* Create content using llhandle */
entry->content = content_create(ctx->llcache,
ctx->child.charset, ctx->child.quirks);
if (entry->content == NULL) {
free(entry);
return NSERROR_NOMEM;
}
/* Insert into cache */
entry->prev = NULL;
entry->next = hlcache_content_list;
if (hlcache_content_list != NULL)
hlcache_content_list->prev = entry;
hlcache_content_list = entry;
} else {
/* Found a suitable content: no longer need low-level handle */
llcache_handle_release(ctx->llcache);
}
/* Associate handle with content */
if (content_add_user(entry->content,
hlcache_content_callback, ctx->handle) == false)
return NSERROR_NOMEM;
/* Associate cache entry with handle */
ctx->handle->entry = entry;
/* Catch handle up with state of content */
if (ctx->handle->cb != NULL) {
content_status status = content_get_status(ctx->handle);
if (status == CONTENT_STATUS_LOADING) {
event.type = CONTENT_MSG_LOADING;
ctx->handle->cb(ctx->handle, &event, ctx->handle->pw);
} else if (status == CONTENT_STATUS_READY) {
event.type = CONTENT_MSG_LOADING;
ctx->handle->cb(ctx->handle, &event, ctx->handle->pw);
if (ctx->handle->cb != NULL) {
event.type = CONTENT_MSG_READY;
ctx->handle->cb(ctx->handle, &event,
ctx->handle->pw);
}
} else if (status == CONTENT_STATUS_DONE) {
event.type = CONTENT_MSG_LOADING;
ctx->handle->cb(ctx->handle, &event, ctx->handle->pw);
if (ctx->handle->cb != NULL) {
event.type = CONTENT_MSG_READY;
ctx->handle->cb(ctx->handle, &event,
ctx->handle->pw);
}
if (ctx->handle->cb != NULL) {
event.type = CONTENT_MSG_DONE;
ctx->handle->cb(ctx->handle, &event,
ctx->handle->pw);
}
}
}
return NSERROR_OK;
}
/**
* Veneer between content callback API and hlcache callback API
*
* \param c Content to emit message for
* \param msg Message to emit
* \param data Data for message
* \param pw Pointer to private data (hlcache_handle)
*/
void hlcache_content_callback(struct content *c, content_msg msg,
union content_msg_data data, void *pw)
{
hlcache_handle *handle = pw;
hlcache_event event;
nserror error = NSERROR_OK;
event.type = msg;
event.data = data;
if (handle->cb != NULL)
error = handle->cb(handle, &event, handle->pw);
if (error != NSERROR_OK)
LOG(("Error in callback: %d", error));
}