src/filebuf.h

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7 #ifndef INCLUDE_filebuf_h__
   8 #define INCLUDE_filebuf_h__
   9
  10 #include "fileops.h"
  11 #include "hash.h"
  12 #include <zlib.h>
  13
  14 #ifdef GIT_THREADS
  15 #       define GIT_FILEBUF_THREADS
  16 #endif
  17
  18 #define GIT_FILEBUF_HASH_CONTENTS               (1 << 0)
  19 #define GIT_FILEBUF_APPEND                              (1 << 2)
  20 #define GIT_FILEBUF_FORCE                               (1 << 3)
  21 #define GIT_FILEBUF_TEMPORARY                   (1 << 4)
  22 #define GIT_FILEBUF_DO_NOT_BUFFER               (1 << 5)
  23 #define GIT_FILEBUF_DEFLATE_SHIFT               (6)
  24
  25 #define GIT_FILELOCK_EXTENSION ".lock\0"
  26 #define GIT_FILELOCK_EXTLENGTH 6
  27
  28 typedef struct git_filebuf git_filebuf;
  29 struct git_filebuf {
  30         char *path_original;
  31         char *path_lock;
  32
  33         int (*write)(git_filebuf *file, void *source, size_t len);
  34
  35         bool compute_digest;
  36         git_hash_ctx digest;
  37
  38         unsigned char *buffer;
  39         unsigned char *z_buf;
  40
  41         z_stream zs;
  42         int flush_mode;
  43
  44         size_t buf_size, buf_pos;
  45         git_file fd;
  46         bool fd_is_open;
  47         bool created_lock;
  48         bool did_rename;
  49         bool do_not_buffer;
  50         int last_error;
  51 };
  52
  53 #define GIT_FILEBUF_INIT {0}
  54
  55 /*
  56  * The git_filebuf object lifecycle is:
  57  * - Allocate git_filebuf, preferably using GIT_FILEBUF_INIT.
  58  *
  59  * - Call git_filebuf_open() to initialize the filebuf for use.
  60  *
  61  * - Make as many calls to git_filebuf_write(), git_filebuf_printf(),
  62  *   git_filebuf_reserve() as you like. The error codes for these
  63  *   functions don't need to be checked. They are stored internally
  64  *   by the file buffer.
  65  *
  66  * - While you are writing, you may call git_filebuf_hash() to get
  67  *   the hash of all you have written so far. This function will
  68  *   fail if any of the previous writes to the buffer failed.
  69  *
  70  * - To close the git_filebuf, you may call git_filebuf_commit() or
  71  *   git_filebuf_commit_at() to save the file, or
  72  *   git_filebuf_cleanup() to abandon the file.  All of these will
  73  *   free the git_filebuf object. Likewise, all of these will fail
  74  *   if any of the previous writes to the buffer failed, and set
  75  *   an error code accordingly.
  76  */
  77 int git_filebuf_write(git_filebuf *lock, const void *buff, size_t len);
  78 int git_filebuf_reserve(git_filebuf *file, void **buff, size_t len);
  79 int git_filebuf_printf(git_filebuf *file, const char *format, ...) GIT_FORMAT_PRINTF(2, 3);
  80
  81 int git_filebuf_open(git_filebuf *lock, const char *path, int flags, mode_t mode);
  82 int git_filebuf_open_withsize(git_filebuf *file, const char *path, int flags, mode_t mode, size_t size);
  83 int git_filebuf_commit(git_filebuf *lock);
  84 int git_filebuf_commit_at(git_filebuf *lock, const char *path);
  85 void git_filebuf_cleanup(git_filebuf *lock);
  86 int git_filebuf_hash(git_oid *oid, git_filebuf *file);
  87 int git_filebuf_flush(git_filebuf *file);
  88 int git_filebuf_stats(time_t *mtime, size_t *size, git_filebuf *file);
  89
  90 #endif