cleanup

1 files changed, 244 insertions, 0 deletions

diff --git a/cache.c b/cache.c
new file mode 100644
index 0000000..0ef110d
--- /dev/null
+++ b/cache.c
@@ -0,0 +1,244 @@
+/*
+    Caching file system proxy
+    Copyright (C) 2004  Miklos Szeredi <miklos@szeredi.hu>
+
+    This program can be distributed under the terms of the GNU GPL.
+    See the file COPYING.
+*/
+
+#define FUSE_USE_VERSION 22
+#include "cache.h"
+#include <stdio.h>
+#include <errno.h>
+#include <glib.h>
+#include <pthread.h>
+
+#define CACHE_TIMEOUT 20
+#define MAX_CACHE_SIZE 10000
+#define CACHE_CLEAN_INTERVAL 60
+
+struct node_attr {
+    struct stat stat;
+    time_t stat_valid;
+    time_t valid;
+};
+
+struct fuse_cache_dirhandle {
+    const char *path;
+    fuse_dirh_t h;
+    fuse_dirfil_t filler;
+};
+
+static struct fuse_cache_operations *next_oper;
+static GHashTable *cache;
+static pthread_mutex_t cache_lock;
+static time_t last_cleaned;
+
+static int cache_clean_entry(void *_key, struct node_attr *node, time_t *now)
+{
+    (void) _key;
+    if (*now > node->valid)
+        return TRUE;
+    else
+        return FALSE;
+}
+
+static void cache_clean(void)
+{
+    time_t now = time(NULL);
+    if (g_hash_table_size(cache) > MAX_CACHE_SIZE ||
+        now > last_cleaned + CACHE_CLEAN_INTERVAL) {
+        g_hash_table_foreach_remove(cache, (GHRFunc) cache_clean_entry, &now);
+        last_cleaned = now;
+    }
+}
+
+static struct node_attr *cache_lookup(const char *path)
+{
+    return (struct node_attr *) g_hash_table_lookup(cache, path);    
+}
+
+static void cache_remove(const char *path)
+{
+    pthread_mutex_lock(&cache_lock);
+    g_hash_table_remove(cache, path);
+    pthread_mutex_unlock(&cache_lock);
+}
+
+static void cache_invalidate(const char *path)
+{
+    cache_remove(path);
+}
+
+static void cache_do_rename(const char *from, const char *to)
+{
+    cache_remove(from);
+    cache_remove(to);
+}
+
+static struct node_attr *cache_get(const char *path)
+{
+    struct node_attr *node = cache_lookup(path);
+    if (node == NULL) {
+        char *pathcopy = g_strdup(path);
+        node = g_new0(struct node_attr, 1);
+        g_hash_table_insert(cache, pathcopy, node);
+    }
+    return node;
+}
+
+static void cache_add_attr(const char *path, const struct stat *stbuf)
+{
+    struct node_attr *node;
+    time_t now;
+
+    pthread_mutex_lock(&cache_lock);
+    node = cache_get(path);
+    now = time(NULL);
+    node->stat = *stbuf;
+    node->stat_valid = time(NULL) + CACHE_TIMEOUT;
+    if (node->stat_valid > node->valid)
+        node->valid = node->stat_valid;
+    cache_clean();
+    pthread_mutex_unlock(&cache_lock);
+}
+
+static int cache_getattr(const char *path, struct stat *stbuf)
+{
+    struct node_attr *node;
+    int err;
+    
+    pthread_mutex_lock(&cache_lock);
+    node = cache_lookup(path);
+    if (node != NULL) {
+        time_t now = time(NULL);
+        if (node->valid - now >= 0) {
+            *stbuf = node->stat;
+            pthread_mutex_unlock(&cache_lock);
+            return 0;
+        }
+    }
+    pthread_mutex_unlock(&cache_lock);
+    err = next_oper->oper.getattr(path, stbuf);
+    if (!err)
+        cache_add_attr(path, stbuf);
+
+    return err;
+}
+
+static int cache_dirfill(fuse_cache_dirh_t ch, const char *name,
+                         const struct stat *stbuf)
+{
+    int err = ch->filler(ch->h, name, 0, 0);
+    if (!err) {
+        char *fullpath = g_strdup_printf("%s/%s",
+                                         !ch->path[1] ? "" : ch->path, name);
+        cache_add_attr(fullpath, stbuf);
+        g_free(fullpath);
+    }
+    return err;
+}
+
+static int cache_getdir(const char *path, fuse_dirh_t h, fuse_dirfil_t filler)
+{
+    struct fuse_cache_dirhandle ch;
+    ch.path = path;
+    ch.h = h;
+    ch.filler = filler;
+    return next_oper->cache_getdir(path, &ch, cache_dirfill);
+}
+
+static int cache_unlink(const char *path)
+{
+    int err = next_oper->oper.unlink(path);
+    if (!err)
+        cache_remove(path);
+    return err;
+}
+
+static int cache_rmdir(const char *path)
+{
+    int err = next_oper->oper.rmdir(path);
+    if (!err)
+        cache_remove(path);
+    return err;
+}
+
+static int cache_rename(const char *from, const char *to)
+{
+    int err = next_oper->oper.rename(from, to);
+    if (!err)
+        cache_do_rename(from, to);
+    return err;
+}
+
+static int cache_chmod(const char *path, mode_t mode)
+{
+    int err = next_oper->oper.chmod(path, mode);
+    if (!err)
+        cache_invalidate(path);
+    return err;
+}
+
+static int cache_chown(const char *path, uid_t uid, gid_t gid)
+{
+    int err = next_oper->oper.chown(path, uid, gid);
+    if (!err)
+        cache_invalidate(path);
+    return err;
+}
+
+static int cache_truncate(const char *path, off_t size)
+{
+    int err = next_oper->oper.truncate(path, size);
+    if (!err)
+        cache_invalidate(path);
+    return err;
+}
+
+static int cache_utime(const char *path, struct utimbuf *buf)
+{
+    int err = next_oper->oper.utime(path, buf);
+    if (!err)
+        cache_invalidate(path);
+    return err;
+}
+
+
+struct fuse_operations *cache_init(struct fuse_cache_operations *oper)
+{
+    static struct fuse_operations cache_oper;
+    next_oper = oper;
+
+    cache_oper.getattr  = oper->oper.getattr ? cache_getattr : NULL;
+    cache_oper.readlink = oper->oper.readlink;
+    cache_oper.getdir   = oper->cache_getdir ? cache_getdir : oper->oper.getdir;
+    cache_oper.mknod    = oper->oper.mknod;
+    cache_oper.mkdir    = oper->oper.mkdir;
+    cache_oper.symlink  = oper->oper.symlink;
+    cache_oper.unlink   = oper->oper.unlink ? cache_unlink : NULL;
+    cache_oper.rmdir    = oper->oper.rmdir ? cache_rmdir : NULL;
+    cache_oper.rename   = oper->oper.rename ? cache_rename : NULL;
+    cache_oper.link     = oper->oper.link;
+    cache_oper.chmod    = oper->oper.chmod ? cache_chmod : NULL;
+    cache_oper.chown    = oper->oper.chown ? cache_chown : NULL;
+    cache_oper.truncate = oper->oper.truncate ? cache_truncate : NULL;
+    cache_oper.utime    = oper->oper.utime ? cache_utime : NULL;
+    cache_oper.open     = oper->oper.open;
+    cache_oper.read     = oper->oper.read;
+    cache_oper.write    = oper->oper.write;
+    cache_oper.statfs   = oper->oper.statfs;
+    cache_oper.release  = oper->oper.release;
+    cache_oper.fsync    = oper->oper.fsync;
+    cache_oper.setxattr = oper->oper.setxattr;
+    cache_oper.getxattr = oper->oper.getxattr;
+    cache_oper.listxattr = oper->oper.listxattr;
+    cache_oper.removexattr = oper->oper.removexattr;
+    pthread_mutex_init(&cache_lock, NULL);
+    cache = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
+    if (cache == NULL) {
+        fprintf(stderr, "failed to create cache\n");
+        return NULL;
+    }
+    return &cache_oper;
+}