fusexmp_fh: avoid unnecessary seeking in readdir

diff --git a/ChangeLog b/ChangeLog
index 2acf5b3cf42c63d9df7e2b168d1a23bc0d9d6ed4..9c259965eb65f1eb3e5bd92a2f341243c2ed5673 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,8 @@
 
        * Block SIGCHLD when executing mount and umount
 
+       * fusexmp_fh: avoid unnecessary seeking in readdir
+
 2008-02-03  Csaba Henk <csaba.henk@creo.hu>
 
        * lib/mount_bsd.c:

diff --git a/example/fusexmp_fh.c b/example/fusexmp_fh.c
index 616c263dd278db423cdf32d35fdb66515d7258f8..494967578b7c111204ff737c2716de25e3086762 100644 (file)
--- a/example/fusexmp_fh.c
+++ b/example/fusexmp_fh.c
@@ -19,6 +19,7 @@
 #include <fuse.h>
 #include <ulockmgr.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -77,36 +78,67 @@ static int xmp_readlink(const char *path, char *buf, size_t size)
        return 0;
 }
 
+struct xmp_dirp {
+       DIR *dp;
+       struct dirent *entry;
+       off_t offset;
+};
+
 static int xmp_opendir(const char *path, struct fuse_file_info *fi)
 {
-       DIR *dp = opendir(path);
-       if (dp == NULL)
-               return -errno;
+       int res;
+       struct xmp_dirp *d = malloc(sizeof(struct xmp_dirp));
+       if (d == NULL)
+               return -ENOMEM;
 
-       fi->fh = (unsigned long) dp;
+       d->dp = opendir(path);
+       if (d->dp == NULL) {
+               res = -errno;
+               free(d);
+               return res;
+       }
+       d->offset = 0;
+       d->entry = NULL;
+
+       fi->fh = (unsigned long) d;
        return 0;
 }
 
-static inline DIR *get_dirp(struct fuse_file_info *fi)
+static inline struct xmp_dirp *get_dirp(struct fuse_file_info *fi)
 {
-       return (DIR *) (uintptr_t) fi->fh;
+       return (struct xmp_dirp *) (uintptr_t) fi->fh;
 }
 
 static int xmp_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                       off_t offset, struct fuse_file_info *fi)
 {
-       DIR *dp = get_dirp(fi);
-       struct dirent *de;
+       struct xmp_dirp *d = get_dirp(fi);
 
        (void) path;
-       seekdir(dp, offset);
-       while ((de = readdir(dp)) != NULL) {
+       if (offset != d->offset) {
+               seekdir(d->dp, offset);
+               d->entry = NULL;
+               d->offset = offset;
+       }
+       while (1) {
                struct stat st;
+               off_t nextoff;
+
+               if (!d->entry) {
+                       d->entry = readdir(d->dp);
+                       if (!d->entry)
+                               break;
+               }
+
                memset(&st, 0, sizeof(st));
-               st.st_ino = de->d_ino;
-               st.st_mode = de->d_type << 12;
-               if (filler(buf, de->d_name, &st, telldir(dp)))
+               st.st_ino = d->entry->d_ino;
+               st.st_mode = d->entry->d_type << 12;
+               nextoff = telldir(d->dp);
+               if (filler(buf, d->entry->d_name, &st, nextoff))
                        break;
+
+               d->entry = NULL;
+               d->offset = nextoff;
        }
 
        return 0;
@@ -114,9 +146,10 @@ static int xmp_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
 
 static int xmp_releasedir(const char *path, struct fuse_file_info *fi)
 {
-       DIR *dp = get_dirp(fi);
+       struct xmp_dirp *d = get_dirp(fi);
        (void) path;
-       closedir(dp);
+       closedir(d->dp);
+       free(d);
        return 0;
 }