src/buffer.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_buffer_h__
   8 #define INCLUDE_buffer_h__
   9
  10 #include "common.h"
  11 #include "git2/strarray.h"
  12 #include "git2/buffer.h"
  13
  14 /* typedef struct {
  15  *      char   *ptr;
  16  *      size_t asize, size;
  17  * } git_buf;
  18  */
  19
  20 extern char git_buf__initbuf[];
  21 extern char git_buf__oom[];
  22
  23 /* Use to initialize buffer structure when git_buf is on stack */
  24 #define GIT_BUF_INIT { git_buf__initbuf, 0, 0 }
  25
  26 GIT_INLINE(bool) git_buf_is_allocated(const git_buf *buf)
  27 {
  28         return (buf->ptr != NULL && buf->asize > 0);
  29 }
  30
  31 /**
  32  * Initialize a git_buf structure.
  33  *
  34  * For the cases where GIT_BUF_INIT cannot be used to do static
  35  * initialization.
  36  */
  37 extern int git_buf_init(git_buf *buf, size_t initial_size);
  38
  39 /**
  40  * Resize the buffer allocation to make more space.
  41  *
  42  * This will attempt to grow the buffer to accommodate the additional size.
  43  * It is similar to `git_buf_grow`, but performs the new size calculation,
  44  * checking for overflow.
  45  *
  46  * Like `git_buf_grow`, if this is a user-supplied buffer, this will allocate
  47  * a new buffer.
  48  */
  49 extern int git_buf_grow_by(git_buf *buffer, size_t additional_size);
  50
  51 /**
  52  * Attempt to grow the buffer to hold at least `target_size` bytes.
  53  *
  54  * If the allocation fails, this will return an error.  If `mark_oom` is true,
  55  * this will mark the buffer as invalid for future operations; if false,
  56  * existing buffer content will be preserved, but calling code must handle
  57  * that buffer was not expanded.  If `preserve_external` is true, then any
  58  * existing data pointed to be `ptr` even if `asize` is zero will be copied
  59  * into the newly allocated buffer.
  60  */
  61 extern int git_buf_try_grow(
  62         git_buf *buf, size_t target_size, bool mark_oom);
  63
  64 /**
  65  * Sanitizes git_buf structures provided from user input.  Users of the
  66  * library, when providing git_buf's, may wish to provide a NULL ptr for
  67  * ease of handling.  The buffer routines, however, expect a non-NULL ptr
  68  * always.  This helper method simply handles NULL input, converting to a
  69  * git_buf__initbuf. If a buffer with a non-NULL ptr is passed in, this method
  70  * assures that the buffer is '\0'-terminated.
  71  */
  72 extern void git_buf_sanitize(git_buf *buf);
  73
  74 extern void git_buf_swap(git_buf *buf_a, git_buf *buf_b);
  75 extern char *git_buf_detach(git_buf *buf);
  76 extern int git_buf_attach(git_buf *buf, char *ptr, size_t asize);
  77
  78 /* Populates a `git_buf` where the contents are not "owned" by the
  79  * buffer, and calls to `git_buf_dispose` will not free the given buf.
  80  */
  81 extern void git_buf_attach_notowned(
  82         git_buf *buf, const char *ptr, size_t size);
  83
  84 /**
  85  * Test if there have been any reallocation failures with this git_buf.
  86  *
  87  * Any function that writes to a git_buf can fail due to memory allocation
  88  * issues.  If one fails, the git_buf will be marked with an OOM error and
  89  * further calls to modify the buffer will fail.  Check git_buf_oom() at the
  90  * end of your sequence and it will be true if you ran out of memory at any
  91  * point with that buffer.
  92  *
  93  * @return false if no error, true if allocation error
  94  */
  95 GIT_INLINE(bool) git_buf_oom(const git_buf *buf)
  96 {
  97         return (buf->ptr == git_buf__oom);
  98 }
  99
 100 /*
 101  * Functions below that return int value error codes will return 0 on
 102  * success or -1 on failure (which generally means an allocation failed).
 103  * Using a git_buf where the allocation has failed with result in -1 from
 104  * all further calls using that buffer.  As a result, you can ignore the
 105  * return code of these functions and call them in a series then just call
 106  * git_buf_oom at the end.
 107  */
 108 int git_buf_sets(git_buf *buf, const char *string);
 109 int git_buf_putc(git_buf *buf, char c);
 110 int git_buf_putcn(git_buf *buf, char c, size_t len);
 111 int git_buf_put(git_buf *buf, const char *data, size_t len);
 112 int git_buf_puts(git_buf *buf, const char *string);
 113 int git_buf_printf(git_buf *buf, const char *format, ...) GIT_FORMAT_PRINTF(2, 3);
 114 int git_buf_vprintf(git_buf *buf, const char *format, va_list ap);
 115 void git_buf_clear(git_buf *buf);
 116 void git_buf_consume_bytes(git_buf *buf, size_t len);
 117 void git_buf_consume(git_buf *buf, const char *end);
 118 void git_buf_truncate(git_buf *buf, size_t len);
 119 void git_buf_shorten(git_buf *buf, size_t amount);
 120 void git_buf_rtruncate_at_char(git_buf *path, char separator);
 121
 122 /** General join with separator */
 123 int git_buf_join_n(git_buf *buf, char separator, int nbuf, ...);
 124 /** Fast join of two strings - first may legally point into `buf` data */
 125 int git_buf_join(git_buf *buf, char separator, const char *str_a, const char *str_b);
 126 /** Fast join of three strings - cannot reference `buf` data */
 127 int git_buf_join3(git_buf *buf, char separator, const char *str_a, const char *str_b, const char *str_c);
 128
 129 /**
 130  * Join two strings as paths, inserting a slash between as needed.
 131  * @return 0 on success, -1 on failure
 132  */
 133 GIT_INLINE(int) git_buf_joinpath(git_buf *buf, const char *a, const char *b)
 134 {
 135         return git_buf_join(buf, '/', a, b);
 136 }
 137
 138 GIT_INLINE(const char *) git_buf_cstr(const git_buf *buf)
 139 {
 140         return buf->ptr;
 141 }
 142
 143 GIT_INLINE(size_t) git_buf_len(const git_buf *buf)
 144 {
 145         return buf->size;
 146 }
 147
 148 void git_buf_copy_cstr(char *data, size_t datasize, const git_buf *buf);
 149
 150 #define git_buf_PUTS(buf, str) git_buf_put(buf, str, sizeof(str) - 1)
 151
 152 GIT_INLINE(ssize_t) git_buf_rfind_next(const git_buf *buf, char ch)
 153 {
 154         ssize_t idx = (ssize_t)buf->size - 1;
 155         while (idx >= 0 && buf->ptr[idx] == ch) idx--;
 156         while (idx >= 0 && buf->ptr[idx] != ch) idx--;
 157         return idx;
 158 }
 159
 160 GIT_INLINE(ssize_t) git_buf_rfind(const git_buf *buf, char ch)
 161 {
 162         ssize_t idx = (ssize_t)buf->size - 1;
 163         while (idx >= 0 && buf->ptr[idx] != ch) idx--;
 164         return idx;
 165 }
 166
 167 GIT_INLINE(ssize_t) git_buf_find(const git_buf *buf, char ch)
 168 {
 169         void *found = memchr(buf->ptr, ch, buf->size);
 170         return found ? (ssize_t)((const char *)found - buf->ptr) : -1;
 171 }
 172
 173 /* Remove whitespace from the end of the buffer */
 174 void git_buf_rtrim(git_buf *buf);
 175
 176 int git_buf_cmp(const git_buf *a, const git_buf *b);
 177
 178 /* Quote and unquote a buffer as specified in
 179  * http://marc.info/?l=git&m=112927316408690&w=2
 180  */
 181 int git_buf_quote(git_buf *buf);
 182 int git_buf_unquote(git_buf *buf);
 183
 184 /* Write data as base64 encoded in buffer */
 185 int git_buf_encode_base64(git_buf *buf, const char *data, size_t len);
 186 /* Decode the given bas64 and write the result to the buffer */
 187 int git_buf_decode_base64(git_buf *buf, const char *base64, size_t len);
 188
 189 /* Write data as "base85" encoded in buffer */
 190 int git_buf_encode_base85(git_buf *buf, const char *data, size_t len);
 191 /* Decode the given "base85" and write the result to the buffer */
 192 int git_buf_decode_base85(git_buf *buf, const char *base64, size_t len, size_t output_len);
 193
 194 /* Decode the given percent-encoded string and write the result to the buffer */
 195 int git_buf_decode_percent(git_buf *buf, const char *str, size_t len);
 196
 197 /*
 198  * Insert, remove or replace a portion of the buffer.
 199  *
 200  * @param buf The buffer to work with
 201  *
 202  * @param where The location in the buffer where the transformation
 203  * should be applied.
 204  *
 205  * @param nb_to_remove The number of chars to be removed. 0 to not
 206  * remove any character in the buffer.
 207  *
 208  * @param data A pointer to the data which should be inserted.
 209  *
 210  * @param nb_to_insert The number of chars to be inserted. 0 to not
 211  * insert any character from the buffer.
 212  *
 213  * @return 0 or an error code.
 214  */
 215 int git_buf_splice(
 216         git_buf *buf,
 217         size_t where,
 218         size_t nb_to_remove,
 219         const char *data,
 220         size_t nb_to_insert);
 221
 222 #endif