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 #include <stdarg.h>
  14
  15 /* typedef struct {
  16  *      char   *ptr;
  17  *      size_t asize, size;
  18  * } git_buf;
  19  */
  20
  21 extern char git_buf__initbuf[];
  22 extern char git_buf__oom[];
  23
  24 /* Use to initialize buffer structure when git_buf is on stack */
  25 #define GIT_BUF_INIT { git_buf__initbuf, 0, 0 }
  26
  27 GIT_INLINE(bool) git_buf_is_allocated(const git_buf *buf)
  28 {
  29         return (buf->ptr != NULL && buf->asize > 0);
  30 }
  31
  32 /**
  33  * Initialize a git_buf structure.
  34  *
  35  * For the cases where GIT_BUF_INIT cannot be used to do static
  36  * initialization.
  37  */
  38 extern void git_buf_init(git_buf *buf, size_t initial_size);
  39
  40 /**
  41  * Attempt to grow the buffer to hold at least `target_size` bytes.
  42  *
  43  * If the allocation fails, this will return an error.  If `mark_oom` is true,
  44  * this will mark the buffer as invalid for future operations; if false,
  45  * existing buffer content will be preserved, but calling code must handle
  46  * that buffer was not expanded.  If `preserve_external` is true, then any
  47  * existing data pointed to be `ptr` even if `asize` is zero will be copied
  48  * into the newly allocated buffer.
  49  */
  50 extern int git_buf_try_grow(
  51         git_buf *buf, size_t target_size, bool mark_oom, bool preserve_external);
  52
  53 extern void git_buf_swap(git_buf *buf_a, git_buf *buf_b);
  54 extern char *git_buf_detach(git_buf *buf);
  55 extern void git_buf_attach(git_buf *buf, char *ptr, size_t asize);
  56
  57 /**
  58  * Test if there have been any reallocation failures with this git_buf.
  59  *
  60  * Any function that writes to a git_buf can fail due to memory allocation
  61  * issues.  If one fails, the git_buf will be marked with an OOM error and
  62  * further calls to modify the buffer will fail.  Check git_buf_oom() at the
  63  * end of your sequence and it will be true if you ran out of memory at any
  64  * point with that buffer.
  65  *
  66  * @return false if no error, true if allocation error
  67  */
  68 GIT_INLINE(bool) git_buf_oom(const git_buf *buf)
  69 {
  70         return (buf->ptr == git_buf__oom);
  71 }
  72
  73 /*
  74  * Functions below that return int value error codes will return 0 on
  75  * success or -1 on failure (which generally means an allocation failed).
  76  * Using a git_buf where the allocation has failed with result in -1 from
  77  * all further calls using that buffer.  As a result, you can ignore the
  78  * return code of these functions and call them in a series then just call
  79  * git_buf_oom at the end.
  80  */
  81 int git_buf_sets(git_buf *buf, const char *string);
  82 int git_buf_putc(git_buf *buf, char c);
  83 int git_buf_put(git_buf *buf, const char *data, size_t len);
  84 int git_buf_puts(git_buf *buf, const char *string);
  85 int git_buf_printf(git_buf *buf, const char *format, ...) GIT_FORMAT_PRINTF(2, 3);
  86 int git_buf_vprintf(git_buf *buf, const char *format, va_list ap);
  87 void git_buf_clear(git_buf *buf);
  88 void git_buf_consume(git_buf *buf, const char *end);
  89 void git_buf_truncate(git_buf *buf, size_t len);
  90 void git_buf_shorten(git_buf *buf, size_t amount);
  91 void git_buf_rtruncate_at_char(git_buf *path, char separator);
  92
  93 int git_buf_join_n(git_buf *buf, char separator, int nbuf, ...);
  94 int git_buf_join(git_buf *buf, char separator, const char *str_a, const char *str_b);
  95
  96 /**
  97  * Join two strings as paths, inserting a slash between as needed.
  98  * @return 0 on success, -1 on failure
  99  */
 100 GIT_INLINE(int) git_buf_joinpath(git_buf *buf, const char *a, const char *b)
 101 {
 102         return git_buf_join(buf, '/', a, b);
 103 }
 104
 105 GIT_INLINE(const char *) git_buf_cstr(const git_buf *buf)
 106 {
 107         return buf->ptr;
 108 }
 109
 110 GIT_INLINE(size_t) git_buf_len(const git_buf *buf)
 111 {
 112         return buf->size;
 113 }
 114
 115 void git_buf_copy_cstr(char *data, size_t datasize, const git_buf *buf);
 116
 117 #define git_buf_PUTS(buf, str) git_buf_put(buf, str, sizeof(str) - 1)
 118
 119 GIT_INLINE(ssize_t) git_buf_rfind_next(const git_buf *buf, char ch)
 120 {
 121         ssize_t idx = (ssize_t)buf->size - 1;
 122         while (idx >= 0 && buf->ptr[idx] == ch) idx--;
 123         while (idx >= 0 && buf->ptr[idx] != ch) idx--;
 124         return idx;
 125 }
 126
 127 GIT_INLINE(ssize_t) git_buf_rfind(const git_buf *buf, char ch)
 128 {
 129         ssize_t idx = (ssize_t)buf->size - 1;
 130         while (idx >= 0 && buf->ptr[idx] != ch) idx--;
 131         return idx;
 132 }
 133
 134 GIT_INLINE(ssize_t) git_buf_find(const git_buf *buf, char ch)
 135 {
 136         void *found = memchr(buf->ptr, ch, buf->size);
 137         return found ? (ssize_t)((const char *)found - buf->ptr) : -1;
 138 }
 139
 140 /* Remove whitespace from the end of the buffer */
 141 void git_buf_rtrim(git_buf *buf);
 142
 143 int git_buf_cmp(const git_buf *a, const git_buf *b);
 144
 145 /* Write data as base64 encoded in buffer */
 146 int git_buf_put_base64(git_buf *buf, const char *data, size_t len);
 147
 148 /*
 149  * Insert, remove or replace a portion of the buffer.
 150  *
 151  * @param buf The buffer to work with
 152  *
 153  * @param where The location in the buffer where the transformation
 154  * should be applied.
 155  *
 156  * @param nb_to_remove The number of chars to be removed. 0 to not
 157  * remove any character in the buffer.
 158  *
 159  * @param data A pointer to the data which should be inserted.
 160  *
 161  * @param nb_to_insert The number of chars to be inserted. 0 to not
 162  * insert any character from the buffer.
 163  *
 164  * @return 0 or an error code.
 165  */
 166 int git_buf_splice(
 167         git_buf *buf,
 168         size_t where,
 169         size_t nb_to_remove,
 170         const char *data,
 171         size_t nb_to_insert);
 172
 173 #endif