performance improvements

1 files changed, 178 insertions, 0 deletions

diff --git a/example/null.c b/example/null.c
new file mode 100644
index 0000000..379ba7a
--- /dev/null
+++ b/example/null.c
@@ -0,0 +1,178 @@
+/*
+    FUSE: Filesystem in Userspace
+    Copyright (C) 2001  Miklos Szeredi (mszeredi@inf.bme.hu)
+
+    This program can be distributed under the terms of the GNU GPL.
+    See the file COPYING.
+*/
+
+#include <fuse.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+#include <time.h>
+
+#define UNUSED __attribute__((unused))
+
+static char *unmount_cmd;
+
+static int null_getattr(const char *path, struct stat *stbuf)
+{
+    if(strcmp(path, "/") != 0)
+        return -ENOENT;
+    
+    stbuf->st_mode = S_IFREG | 0644;
+    stbuf->st_nlink = 1;
+    stbuf->st_uid = getuid();
+    stbuf->st_gid = getgid();
+    stbuf->st_size = (1 << 30); /* 1G */
+    stbuf->st_blocks = 0;
+    stbuf->st_atime = stbuf->st_mtime = stbuf->st_ctime = time(NULL);
+
+    return 0;
+}
+
+static int null_truncate(const char *path, off_t UNUSED(size))
+{
+    if(strcmp(path, "/") != 0)
+        return -ENOENT;
+
+    return 0;
+}
+
+static int null_open(const char *path, int UNUSED(flags))
+{
+    if(strcmp(path, "/") != 0)
+        return -ENOENT;
+
+    return 0;
+}
+
+static int null_read(const char *path, char *UNUSED(buf), size_t size,
+                     off_t UNUSED(offset))
+{
+    if(strcmp(path, "/") != 0)
+        return -ENOENT;
+
+    return size;
+}
+
+static int null_write(const char *path, const char *UNUSED(buf), size_t size,
+                     off_t UNUSED(offset))
+{
+    if(strcmp(path, "/") != 0)
+        return -ENOENT;
+
+    return size;
+}
+
+
+static struct fuse_operations null_oper = {
+    getattr:	null_getattr,
+    readlink:	NULL,
+    getdir:     NULL,
+    mknod:	NULL,
+    mkdir:	NULL,
+    symlink:	NULL,
+    unlink:	NULL,
+    rmdir:	NULL,
+    rename:     NULL,
+    link:	NULL,
+    chmod:	NULL,
+    chown:	NULL,
+    truncate:	null_truncate,
+    utime:	NULL,
+    open:	null_open,
+    read:	null_read,
+    write:	null_write,
+};
+
+
+static void exit_handler()
+{
+    close(0);
+    system(unmount_cmd);    
+    exit(0);
+}
+
+static void set_signal_handlers()
+{
+    struct sigaction sa;
+
+    sa.sa_handler = exit_handler;
+    sigemptyset(&(sa.sa_mask));
+    sa.sa_flags = 0;
+
+    if (sigaction(SIGHUP, &sa, NULL) == -1 || 
+	sigaction(SIGINT, &sa, NULL) == -1 || 
+	sigaction(SIGTERM, &sa, NULL) == -1) {
+	
+	perror("Cannot set exit signal handlers");
+        exit(1);
+    }
+
+    sa.sa_handler = SIG_IGN;
+    
+    if(sigaction(SIGPIPE, &sa, NULL) == -1) {
+	perror("Cannot set ignored signals");
+        exit(1);
+    }
+}
+
+int main(int argc, char *argv[])
+{
+    int argctr;
+    int flags;
+    int multithreaded;
+    struct fuse *fuse;
+
+    if(argc < 2) {
+        fprintf(stderr,
+                "usage: %s unmount_cmd [options] \n"
+                "Options:\n"
+                "    -d      enable debug output\n"
+                "    -s      disable multithreaded operation\n",
+                argv[0]);
+        exit(1);
+    }
+
+    argctr = 1;
+    unmount_cmd = argv[argctr++];
+
+    set_signal_handlers();
+
+    flags = 0;
+    multithreaded = 1;
+    for(; argctr < argc && argv[argctr][0] == '-'; argctr ++) {
+        switch(argv[argctr][1]) {
+        case 'd':
+            flags |= FUSE_DEBUG;
+            break;
+
+        case 's':
+            multithreaded = 0;
+            break;
+
+        default:
+            fprintf(stderr, "invalid option: %s\n", argv[argctr]);
+            exit(1);
+        }
+    }
+    if(argctr != argc) {
+        fprintf(stderr, "missing or surplus argument\n");
+        exit(1);
+    }
+
+    fuse = fuse_new(0, flags);
+    fuse_set_operations(fuse, &null_oper);
+
+    if(multithreaded)
+        fuse_loop_mt(fuse);
+    else
+        fuse_loop(fuse);
+
+    return 0;
+}