From 71de3618f16f43e5fb4fabff5bba66649a8b9595 Mon Sep 17 00:00:00 2001
From: John Mark Bell <jmb@netsurf-browser.org>
Date: Sun, 11 Apr 2010 20:21:13 +0000
Subject: Implement hlcache_poll(), which drives the low-level cache event
 loop, and attempts to clean the high-level cache. Call this, instead of
 llcache_poll().

svn path=/trunk/netsurf/; revision=10371
---
 content/hlcache.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 content/hlcache.h |  8 ++++++++
 desktop/netsurf.c |  4 ++--
 3 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/content/hlcache.c b/content/hlcache.c
index 2a3305387..dd520c8c6 100644
--- a/content/hlcache.c
+++ b/content/hlcache.c
@@ -73,6 +73,7 @@ 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, 
@@ -86,6 +87,17 @@ static void hlcache_content_callback(struct content *c,
  * Public API								      *
  ******************************************************************************/
 
+/* See hlcache.h for documentation */
+nserror hlcache_poll(void)
+{
+	llcache_poll();
+
+	/* Give the cache a clean */
+	hlcache_clean();
+
+	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,
@@ -266,6 +278,46 @@ nserror hlcache_handle_abort(hlcache_handle *handle)
  * 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
  *
diff --git a/content/hlcache.h b/content/hlcache.h
index 9f03052fa..1c4cc7b2f 100644
--- a/content/hlcache.h
+++ b/content/hlcache.h
@@ -63,6 +63,14 @@ enum hlcache_retrieve_flag {
 	HLCACHE_RETRIEVE_MAY_DOWNLOAD = (1 << 31)
 };
 
+/**
+ * Drive the low-level cache poll loop, and attempt to clean the cache.
+ * No guarantee is made about what, if any, cache cleaning will occur.
+ *
+ * \return NSERROR_OK
+ */
+nserror hlcache_poll(void);
+
 /**
  * Retrieve a high-level cache handle for an object
  *
diff --git a/desktop/netsurf.c b/desktop/netsurf.c
index 248f6fef0..fcd44f642 100644
--- a/desktop/netsurf.c
+++ b/desktop/netsurf.c
@@ -33,7 +33,7 @@
 #include "utils/config.h"
 #include "utils/utsname.h"
 #include "content/fetch.h"
-#include "content/llcache.h"
+#include "content/hlcache.h"
 #include "content/urldb.h"
 #include "desktop/netsurf.h"
 #include "desktop/browser.h"
@@ -136,7 +136,7 @@ int netsurf_main_loop(void)
 {
 	while (!netsurf_quit) {
 		gui_poll(fetch_active);
-		llcache_poll();
+		hlcache_poll();
 	}
 
 	return 0;
-- 
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