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+/*
+** Copyright (c) 2014 D. Richard Hipp
+**
+** This program is free software; you can redistribute it and/or
+** modify it under the terms of the Simplified BSD License (also
+** known as the "2-Clause License" or "FreeBSD License".)
+**
+** This program 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.
+**
+** Author contact information:
+** drh@sqlite.org
+** http://www.hwaci.com/drh/
+**
+*******************************************************************************
+**
+** This module implements the userspace side of a Fuse Filesystem that
+** contains all check-ins for a fossil repository.
+**
+** This module is a mostly a no-op unless compiled with -DFOSSIL_HAVE_FUSEFS.
+** The FOSSIL_HAVE_FUSEFS should be omitted on systems that lack support for
+** the Fuse Filesystem, of course.
+*/
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+#ifdef FOSSIL_HAVE_FUSEFS
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include "fusefs.h"
+
+#define FUSE_USE_VERSION 26
+#include <fuse.h>
+
+/*
+** Global state information about the archive
+*/
+static struct sGlobal {
+ /* A cache of a single check-in manifest */
+ int rid; /* rid for the cached manifest */
+ char *zSymName; /* Symbolic name corresponding to rid */
+ Manifest *pMan; /* The cached manifest */
+ /* A cache of a single file within a single check-in */
+ int iFileRid; /* Check-in ID for the cached file */
+ ManifestFile *pFile; /* Name of a cached file */
+ Blob content; /* Content of the cached file */
+ /* Parsed path */
+ char *az[3]; /* 0=type, 1=id, 2=path */
+} fusefs;
+
+/*
+** Clear the fusefs.az[] array.
+*/
+static void fusefs_clear_path(void){
+ int i;
+ for(i=0; i<count(fusefs.az); i++){
+ fossil_free(fusefs.az[i]);
+ fusefs.az[i] = 0;
+ }
+}
+
+/*
+** Split of the input path into 0, 1, 2, or 3 elements in fusefs.az[].
+** Return the number of elements.
+**
+** Any prior path parse is deleted.
+*/
+static int fusefs_parse_path(const char *zPath){
+ int i, j;
+ fusefs_clear_path();
+ if( strcmp(zPath,"/")==0 ) return 0;
+ for(i=0, j=1; i<2 && zPath[j]; i++){
+ int jStart = j;
+ while( zPath[j] && zPath[j]!='/' ){ j++; }
+ fusefs.az[i] = mprintf("%.*s", j-jStart, &zPath[jStart]);
+ if( zPath[j] ) j++;
+ }
+ if( zPath[j] ) fusefs.az[i++] = fossil_strdup(&zPath[j]);
+ return i;
+}
+
+/*
+** Reclaim memory used by the fusefs local variable.
+*/
+static void fusefs_reset(void){
+ blob_reset(&fusefs.content);
+ manifest_destroy(fusefs.pMan);
+ fusefs.pMan = 0;
+ fossil_free(fusefs.zSymName);
+ fusefs.zSymName = 0;
+ fusefs.pFile = 0;
+}
+
+/*
+** Load manifest rid into the cache.
+*/
+static void fusefs_load_rid(int rid, const char *zSymName){
+ if( fusefs.rid==rid && fusefs.pMan!=0 ) return;
+ fusefs_reset();
+ fusefs.zSymName = fossil_strdup(zSymName);
+ fusefs.pMan = manifest_get(rid, CFTYPE_MANIFEST, 0);
+ fusefs.rid = rid;
+}
+
+/*
+** Locate the rid corresponding to a symbolic name
+*/
+static int fusefs_name_to_rid(const char *zSymName){
+ if( fusefs.rid>0 && strcmp(zSymName, fusefs.zSymName)==0 ){
+ return fusefs.rid;
+ }else{
+ return symbolic_name_to_rid(zSymName, "ci");
+ }
+}
+
+
+/*
+** Implementation of stat()
+*/
+static int fusefs_getattr(const char *zPath, struct stat *stbuf){
+ int n, rid;
+ ManifestFile *pFile;
+ char *zDir;
+ stbuf->st_uid = getuid();
+ stbuf->st_gid = getgid();
+ n = fusefs_parse_path(zPath);
+ if( n==0 ){
+ stbuf->st_mode = S_IFDIR | 0555;
+ stbuf->st_nlink = 2;
+ return 0;
+ }
+ if( strcmp(fusefs.az[0],"checkins")!=0 ) return -ENOENT;
+ if( n==1 ){
+ stbuf->st_mode = S_IFDIR | 0111;
+ stbuf->st_nlink = 2;
+ return 0;
+ }
+ rid = fusefs_name_to_rid(fusefs.az[1]);
+ if( rid<=0 ) return -ENOENT;
+ if( n==2 ){
+ stbuf->st_mode = S_IFDIR | 0555;
+ stbuf->st_nlink = 2;
+ return 0;
+ }
+ fusefs_load_rid(rid, fusefs.az[1]);
+ if( fusefs.pMan==0 ) return -ENOENT;
+ stbuf->st_mtime = (fusefs.pMan->rDate - 2440587.5)*86400.0;
+ pFile = manifest_file_seek(fusefs.pMan, fusefs.az[2], 0);
+ if( pFile ){
+ static Stmt q;
+ stbuf->st_mode = S_IFREG |
+ (manifest_file_mperm(pFile)==PERM_EXE ? 0555 : 0444);
+ stbuf->st_nlink = 1;
+ db_static_prepare(&q, "SELECT size FROM blob WHERE uuid=$uuid");
+ db_bind_text(&q, "$uuid", pFile->zUuid);
+ if( db_step(&q)==SQLITE_ROW ){
+ stbuf->st_size = db_column_int(&q, 0);
+ }
+ db_reset(&q);
+ return 0;
+ }
+ zDir = mprintf("%s/", fusefs.az[2]);
+ pFile = manifest_file_seek(fusefs.pMan, zDir, 1);
+ fossil_free(zDir);
+ if( pFile==0 ) return -ENOENT;
+ n = (int)strlen(fusefs.az[2]);
+ if( strncmp(fusefs.az[2], pFile->zName, n)!=0 ) return -ENOENT;
+ if( pFile->zName[n]!='/' ) return -ENOENT;
+ stbuf->st_mode = S_IFDIR | 0555;
+ stbuf->st_nlink = 2;
+ return 0;
+}
+
+/*
+** Implementation of readdir()
+*/
+static int fusefs_readdir(
+ const char *zPath,
+ void *buf,
+ fuse_fill_dir_t filler,
+ off_t offset,
+ struct fuse_file_info *fi
+){
+ int n, rid;
+ ManifestFile *pFile;
+ const char *zPrev = "";
+ int nPrev = 0;
+ char *z;
+ int cnt = 0;
+ n = fusefs_parse_path(zPath);
+ if( n==0 ){
+ filler(buf, ".", NULL, 0);
+ filler(buf, "..", NULL, 0);
+ filler(buf, "checkins", NULL, 0);
+ return 0;
+ }
+ if( strcmp(fusefs.az[0],"checkins")!=0 ) return -ENOENT;
+ if( n==1 ) return -ENOENT;
+ rid = fusefs_name_to_rid(fusefs.az[1]);
+ if( rid<=0 ) return -ENOENT;
+ fusefs_load_rid(rid, fusefs.az[1]);
+ if( fusefs.pMan==0 ) return -ENOENT;
+ filler(buf, ".", NULL, 0);
+ filler(buf, "..", NULL, 0);
+ manifest_file_rewind(fusefs.pMan);
+ if( n==2 ){
+ while( (pFile = manifest_file_next(fusefs.pMan, 0))!=0 ){
+ if( nPrev>0 && strncmp(pFile->zName, zPrev, nPrev)==0
+ && pFile->zName[nPrev]=='/' ) continue;
+ zPrev = pFile->zName;
+ for(nPrev=0; zPrev[nPrev] && zPrev[nPrev]!='/'; nPrev++){}
+ z = mprintf("%.*s", nPrev, zPrev);
+ filler(buf, z, NULL, 0);
+ fossil_free(z);
+ cnt++;
+ }
+ }else{
+ char *zBase = mprintf("%s/", fusefs.az[2]);
+ int nBase = (int)strlen(zBase);
+ while( (pFile = manifest_file_next(fusefs.pMan, 0))!=0 ){
+ if( strcmp(pFile->zName, zBase)>=0 ) break;
+ }
+ while( pFile && strncmp(zBase, pFile->zName, nBase)==0 ){
+ if( nPrev==0 || strncmp(pFile->zName+nBase, zPrev, nPrev)!=0 ){
+ zPrev = pFile->zName+nBase;
+ for(nPrev=0; zPrev[nPrev] && zPrev[nPrev]!='/'; nPrev++){}
+ if( zPrev[nPrev]=='/' ){
+ z = mprintf("%.*s", nPrev, zPrev);
+ filler(buf, z, NULL, 0);
+ fossil_free(z);
+ }else{
+ filler(buf, zPrev, NULL, 0);
+ nPrev = 0;
+ }
+ cnt++;
+ }
+ pFile = manifest_file_next(fusefs.pMan, 0);
+ }
+ fossil_free(zBase);
+ }
+ return cnt>0 ? 0 : -ENOENT;
+}
+
+
+/*
+** Implementation of read()
+*/
+static int fusefs_read(
+ const char *zPath,
+ char *buf,
+ size_t size,
+ off_t offset,
+ struct fuse_file_info *fi
+){
+ int n, rid;
+ n = fusefs_parse_path(zPath);
+ if( n<3 ) return -ENOENT;
+ if( strcmp(fusefs.az[0], "checkins")!=0 ) return -ENOENT;
+ rid = fusefs_name_to_rid(fusefs.az[1]);
+ if( rid<=0 ) return -ENOENT;
+ fusefs_load_rid(rid, fusefs.az[1]);
+ if( fusefs.pFile!=0 && strcmp(fusefs.az[2], fusefs.pFile->zName)!=0 ){
+ fusefs.pFile = 0;
+ blob_reset(&fusefs.content);
+ }
+ fusefs.pFile = manifest_file_seek(fusefs.pMan, fusefs.az[2], 0);
+ if( fusefs.pFile==0 ) return -ENOENT;
+ rid = uuid_to_rid(fusefs.pFile->zUuid, 0);
+ blob_reset(&fusefs.content);
+ content_get(rid, &fusefs.content);
+ if( offset>blob_size(&fusefs.content) ) return 0;
+ if( offset+size>blob_size(&fusefs.content) ){
+ size = blob_size(&fusefs.content) - offset;
+ }
+ memcpy(buf, blob_buffer(&fusefs.content)+offset, size);
+ return size;
+}
+
+static struct fuse_operations fusefs_methods = {
+ .getattr = fusefs_getattr,
+ .readdir = fusefs_readdir,
+ .read = fusefs_read,
+};
+#endif /* FOSSIL_HAVE_FUSEFS */
+
+/*
+** COMMAND: fusefs*
+**
+** Usage: %fossil fusefs [--debug] DIRECTORY
+**
+** This command uses the Fuse Filesystem (FuseFS) to mount a directory
+** at DIRECTORY that contains the content of all check-ins in the
+** repository. The names of files are DIRECTORY/checkins/VERSION/PATH
+** where DIRECTORY is the root of the mount, VERSION is any valid
+** check-in name (examples: "trunk" or "tip" or a tag or any unique
+** prefix of an artifact hash, etc) and PATH is the pathname of the file in
+** the check-in. If DIRECTORY does not exist, then an attempt is made
+** to create it.
+**
+** The DIRECTORY/checkins directory is not searchable so one cannot
+** do "ls DIRECTORY/checkins" to get a listing of all possible check-in
+** names. There are countless variations on check-in names and it is
+** impractical to list them all. But all other directories are searchable
+** and so the "ls" command will work everywhere else in the fusefs
+** file hierarchy.
+**
+** The FuseFS typically only works on Linux, and then only on Linux
+** systems that have the right kernel drivers and have installed the
+** appropriate support libraries.
+**
+** After stopping the "fossil fusefs" command, it might also be necessary
+** to run "fusermount -u DIRECTORY" to reset the FuseFS before using it
+** again.
+*/
+void fusefs_cmd(void){
+#ifdef FOSSIL_HAVE_FUSEFS
+ char *zMountPoint;
+ char *azNewArgv[5];
+ int doDebug = find_option("debug","d",0)!=0;
+
+ db_find_and_open_repository(0,0);
+ verify_all_options();
+ blob_init(&fusefs.content, 0, 0);
+ if( g.argc!=3 ) usage("DIRECTORY");
+ zMountPoint = g.argv[2];
+ if( file_mkdir(zMountPoint, ExtFILE, 0) ){
+ fossil_fatal("cannot make directory [%s]", zMountPoint);
+ }
+ azNewArgv[0] = g.argv[0];
+ azNewArgv[1] = doDebug ? "-d" : "-f";
+ azNewArgv[2] = "-s";
+ azNewArgv[3] = zMountPoint;
+ azNewArgv[4] = 0;
+ g.localOpen = 0; /* Prevent tags like "current" and "prev" */
+ fuse_main(4, azNewArgv, &fusefs_methods, NULL);
+ fusefs_reset();
+ fusefs_clear_path();
+#else
+ fprintf(stderr, "The FuseFS is not available in this build.\n");
+ exit(1);
+#endif /* FOSSIL_HAVE_FUSEFS */
+}
+
+/*
+** Return version numbers for the FUSE header that was used at compile-time
+** and/or the FUSE library that was loaded at runtime.
+*/
+const char *fusefs_lib_version(void){
+#if defined(FOSSIL_HAVE_FUSEFS) && FUSE_MAJOR_VERSION>=3
+ return fuse_pkgversion();
+#else
+ return "unknown";
+#endif
+}
+
+const char *fusefs_inc_version(void){
+#ifdef FOSSIL_HAVE_FUSEFS
+ return COMPILER_STRINGIFY(FUSE_MAJOR_VERSION) "."
+ COMPILER_STRINGIFY(FUSE_MINOR_VERSION);
+#else
+ return "unknown";
+#endif
+}
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