lock.c

subversion-1.4.3-1.tar.gz 配置svn的源码

/* lock.c :  functions for manipulating filesystem locks.
 *
 * ====================================================================
 * Copyright (c) 2000-2004 CollabNet.  All rights reserved.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution.  The terms
 * are also available at http://subversion.tigris.org/license-1.html.
 * If newer versions of this license are posted there, you may use a
 * newer version instead, at your option.
 *
 * This software consists of voluntary contributions made by many
 * individuals.  For exact contribution history, see the revision
 * history and logs, available at http://subversion.tigris.org/.
 * ====================================================================
 */


#include <assert.h>
#include "svn_pools.h"
#include "svn_error.h"
#include "svn_path.h"
#include "svn_fs.h"
#include "svn_hash.h"
#include "svn_time.h"
#include "svn_utf.h"
#include "svn_md5.h"

#include <apr_uuid.h>
#include <apr_file_io.h>
#include <apr_file_info.h>
#include <apr_md5.h>

#include "lock.h"
#include "tree.h"
#include "err.h"
#include "fs_fs.h"
#include "../libsvn_fs/fs-loader.h"

#include "svn_private_config.h"

/* Names of special lock directories in the fs_fs filesystem. */
#define LOCK_ROOT_DIR "locks"

/* Names of hash keys used to store a lock for writing to disk. */
#define PATH_KEY "path"
#define TOKEN_KEY "token"
#define OWNER_KEY "owner"
#define CREATION_DATE_KEY "creation_date"
#define EXPIRATION_DATE_KEY "expiration_date"
#define COMMENT_KEY "comment"
#define IS_DAV_COMMENT_KEY "is_dav_comment"
#define CHILDREN_KEY "children"

/* Number of characters from the head of a digest file name used to
   calculate a subdirectory in which to drop that file. */
#define DIGEST_SUBDIR_LEN 3



/*** Generic helper functions. ***/

/* Return the MD5 hash of STR. */
static const char *
make_digest(const char *str,
            apr_pool_t *pool)
{
  unsigned char digest[APR_MD5_DIGESTSIZE];

  apr_md5(digest, str, strlen(str));
  return svn_md5_digest_to_cstring_display(digest, pool);
}


/* Set the value of KEY (whose size is KEY_LEN, or APR_HASH_KEY_STRING
   if unknown) to an svn_string_t-ized version of VALUE (whose size is
   VALUE_LEN, or APR_HASH_KEY_STRING if unknown) in HASH.  The value
   will be allocated in POOL; KEY will not be duped.  If either KEY or VALUE
   is NULL, this function will do nothing. */
static void
hash_store(apr_hash_t *hash,
           const char *key,
           apr_ssize_t key_len,
           const char *value,
           apr_ssize_t value_len,
           apr_pool_t *pool)
{
  if (! (key && value))
    return;
  if (value_len == APR_HASH_KEY_STRING)
    value_len = strlen(value);
  apr_hash_set(hash, key, key_len, 
               svn_string_ncreate(value, value_len, pool));
}


/* Fetch the value of KEY from HASH, returning only the cstring data
   of that value (if it exists). */
static const char *
hash_fetch(apr_hash_t *hash,
           const char *key,
           apr_pool_t *pool)
{
  svn_string_t *str = apr_hash_get(hash, key, APR_HASH_KEY_STRING);
  return str ? str->data : NULL;
}



/*** Digest file handling functions. ***/

/* Return the path of the lock/entries file for which DIGEST is the
   hashed repository relative path. */
static const char *
digest_path_from_digest(svn_fs_t *fs,
                        const char *digest,
                        apr_pool_t *pool)
{
  return svn_path_join_many(pool, fs->path, LOCK_ROOT_DIR, 
                            apr_pstrmemdup(pool, digest, DIGEST_SUBDIR_LEN), 
                            digest, NULL);
}


/* Return the path to the lock/entries digest file associate with
   PATH, where PATH is the path to the lock file or lock entries file
   in FS. */
static const char *
digest_path_from_path(svn_fs_t *fs,
                      const char *path,
                      apr_pool_t *pool)
{
  const char *digest = make_digest(path, pool);
  return svn_path_join_many(pool, fs->path, LOCK_ROOT_DIR, 
                            apr_pstrmemdup(pool, digest, DIGEST_SUBDIR_LEN), 
                            digest, NULL);
}


/* If directory PATH does not exist, create it and give it the same
   permissions as FS->path.*/
static svn_error_t *
ensure_dir_exists(const char *path,
                  svn_fs_t *fs,
                  apr_pool_t *pool)
{
  svn_error_t *err = svn_io_dir_make(path, APR_OS_DEFAULT, pool);
  if (err && APR_STATUS_IS_EEXIST(err->apr_err))
    {
      svn_error_clear(err);
      return SVN_NO_ERROR;
    }
  SVN_ERR(err);

  /* We successfully created a new directory.  Dup the permissions
     from FS->path. */
  SVN_ERR(svn_fs_fs__dup_perms(path, fs->path, pool));

  return SVN_NO_ERROR;
}


/* Write to DIGEST_PATH a representation of CHILDREN (which may be
   empty, if the versioned path in FS represented by DIGEST_PATH has
   no children) and LOCK (which may be NULL if that versioned path is
   lock itself locked).  Use POOL for all allocations. */
static svn_error_t *
write_digest_file(apr_hash_t *children,
                  svn_lock_t *lock,
                  svn_fs_t *fs,
                  const char *digest_path,
                  apr_pool_t *pool)
{
  svn_error_t *err = SVN_NO_ERROR;
  apr_file_t *fd;
  apr_hash_index_t *hi;
  apr_hash_t *hash = apr_hash_make(pool);
  const char *tmp_path;

  SVN_ERR(ensure_dir_exists(svn_path_join(fs->path, LOCK_ROOT_DIR, pool), 
                            fs, pool));
  SVN_ERR(ensure_dir_exists(svn_path_dirname(digest_path, pool), fs, pool));
  SVN_ERR(svn_io_open_unique_file2
          (&fd, &tmp_path, digest_path, ".tmp", svn_io_file_del_none, pool));

  if (lock)
    {
      const char *creation_date = NULL, *expiration_date = NULL;
      if (lock->creation_date)
        creation_date = svn_time_to_cstring(lock->creation_date, pool);
      if (lock->expiration_date)
        expiration_date = svn_time_to_cstring(lock->expiration_date, pool);
      hash_store(hash, PATH_KEY, sizeof(PATH_KEY)-1,
                 lock->path, APR_HASH_KEY_STRING, pool); 
      hash_store(hash, TOKEN_KEY, sizeof(TOKEN_KEY)-1,
                 lock->token, APR_HASH_KEY_STRING, pool); 
      hash_store(hash, OWNER_KEY, sizeof(OWNER_KEY)-1,
                 lock->owner, APR_HASH_KEY_STRING, pool); 
      hash_store(hash, COMMENT_KEY, sizeof(COMMENT_KEY)-1,
                 lock->comment, APR_HASH_KEY_STRING, pool); 
      hash_store(hash, IS_DAV_COMMENT_KEY, sizeof(IS_DAV_COMMENT_KEY)-1,
                 lock->is_dav_comment ? "1" : "0", 1, pool);
      hash_store(hash, CREATION_DATE_KEY, sizeof(CREATION_DATE_KEY)-1,
                 creation_date, APR_HASH_KEY_STRING, pool);
      hash_store(hash, EXPIRATION_DATE_KEY, sizeof(EXPIRATION_DATE_KEY)-1,
                 expiration_date, APR_HASH_KEY_STRING, pool);
    }
  if (apr_hash_count(children))
    {
      svn_stringbuf_t *children_list = svn_stringbuf_create("", pool);
      for (hi = apr_hash_first(pool, children); hi; hi = apr_hash_next(hi)) 
        {
          const void *key;
          apr_ssize_t klen;
          apr_hash_this(hi, &key, &klen, NULL);
          svn_stringbuf_appendbytes(children_list, key, klen);
          svn_stringbuf_appendbytes(children_list, "\n", 1);
        }
      hash_store(hash, CHILDREN_KEY, sizeof(CHILDREN_KEY)-1,
                 children_list->data, children_list->len, pool);
    } 

  if ((err = svn_hash_write2(hash, 
                             svn_stream_from_aprfile(fd, pool),
                             SVN_HASH_TERMINATOR, pool)))
    {
      svn_error_clear(svn_io_file_close(fd, pool));
      return svn_error_createf(err->apr_err,
                               err,
                               _("Cannot write lock/entries hashfile '%s'"),
                               svn_path_local_style(tmp_path, pool));
    }

  SVN_ERR(svn_io_file_close(fd, pool));
  SVN_ERR(svn_io_file_rename(tmp_path, digest_path, pool));
  SVN_ERR(svn_fs_fs__dup_perms 
          (digest_path, svn_fs_fs__path_rev(fs, 0, pool), pool));

  return SVN_NO_ERROR;
}


/* Parse the file at DIGEST_PATH, populating the lock LOCK_P in that
   file (if it exists, and if *LOCK_P is non-NULL) and the hash of
   CHILDREN_P (if any exist, and if *CHILDREN_P is non-NULL).  Use POOL
   for all allocations.  */
static svn_error_t *
read_digest_file(apr_hash_t **children_p,
                 svn_lock_t **lock_p,
                 svn_fs_t *fs,
                 const char *digest_path,
                 apr_pool_t *pool)
{
  svn_error_t *err = SVN_NO_ERROR;
  svn_lock_t *lock;
  apr_hash_t *hash;
  apr_file_t *fd;
  const char *val;

  if (lock_p)
    *lock_p = NULL;
  if (children_p)
    *children_p = apr_hash_make(pool);

  err = svn_io_file_open(&fd, digest_path, APR_READ, APR_OS_DEFAULT, pool);
  if (err && APR_STATUS_IS_ENOENT(err->apr_err))
    {
      svn_error_clear(err);
      return SVN_NO_ERROR;
    }
  SVN_ERR(err);

  /* If our caller doesn't care about anything but the presence of the
     file... whatever. */
  if (! (lock_p || children_p))
    return svn_io_file_close(fd, pool);

  hash = apr_hash_make(pool);
  if ((err = svn_hash_read2(hash, 
                            svn_stream_from_aprfile(fd, pool),
                            SVN_HASH_TERMINATOR, pool)))
    {
      svn_error_clear(svn_io_file_close(fd, pool));
      return svn_error_createf(err->apr_err,
                               err,
                               _("Can't parse lock/entries hashfile '%s'"),
                               svn_path_local_style(digest_path, pool));
    }
  SVN_ERR(svn_io_file_close(fd, pool));

  /* If our caller cares, see if we have a lock path in our hash. If
     so, we'll assume we have a lock here. */
  val = hash_fetch(hash, PATH_KEY, pool);
  if (val && lock_p)
    {
      const char *path = val;

      /* Create our lock and load it up. */
      lock = svn_lock_create(pool);
      lock->path = path;

      if (! ((lock->token = hash_fetch(hash, TOKEN_KEY, pool))))
        return svn_fs_fs__err_corrupt_lockfile(fs, path);

      if (! ((lock->owner = hash_fetch(hash, OWNER_KEY, pool))))
        return svn_fs_fs__err_corrupt_lockfile(fs, path);

      if (! ((val = hash_fetch(hash, IS_DAV_COMMENT_KEY, pool))))
        return svn_fs_fs__err_corrupt_lockfile(fs, path);
      lock->is_dav_comment = (val[0] == '1') ? TRUE : FALSE;

      if (! ((val = hash_fetch(hash, CREATION_DATE_KEY, pool))))
        return svn_fs_fs__err_corrupt_lockfile(fs, path);
      SVN_ERR(svn_time_from_cstring(&(lock->creation_date), val, pool));