subversion/include/svn_string.h

   1 /**
   2  * @copyright
   3  * ====================================================================
   4  * Copyright (c) 2000-2006 CollabNet.  All rights reserved.
   5  *
   6  * This software is licensed as described in the file COPYING, which
   7  * you should have received as part of this distribution.  The terms
   8  * are also available at http://subversion.tigris.org/license-1.html.
   9  * If newer versions of this license are posted there, you may use a
  10  * newer version instead, at your option.
  11  *
  12  * This software consists of voluntary contributions made by many
  13  * individuals.  For exact contribution history, see the revision
  14  * history and logs, available at http://subversion.tigris.org/.
  15  * ====================================================================
  16  * @endcopyright
  17  *
  18  * @file svn_string.h
  19  * @brief Counted-length strings for Subversion, plus some C string goodies.
  20  *
  21  * There are two string datatypes: @c svn_string_t and @c svn_stringbuf_t.
  22  * The former is a simple pointer/length pair useful for passing around
  23  * strings (or arbitrary bytes) with a counted length. @c svn_stringbuf_t is
  24  * buffered to enable efficient appending of strings without an allocation
  25  * and copy for each append operation.
  26  *
  27  * @c svn_string_t contains a <tt>const char *</tt> for its data, so it is
  28  * most appropriate for constant data and for functions which expect constant,
  29  * counted data. Functions should generally use <tt>const @c svn_string_t
  30  * *</tt> as their parameter to indicate they are expecting a constant,
  31  * counted string.
  32  *
  33  * @c svn_stringbuf_t uses a plain <tt>char *</tt> for its data, so it is
  34  * most appropriate for modifiable data.
  35  *
  36  * <h3>Invariants</h3>
  37  *
  38  *   1. Null termination:
  39  *
  40  *      Both structures maintain a significant invariant:
  41  *
  42  *         <tt>s->data[s->len] == '\\0'</tt>
  43  *
  44  *      The functions defined within this header file will maintain
  45  *      the invariant (which does imply that memory is
  46  *      allocated/defined as @c len+1 bytes).  If code outside of the
  47  *      @c svn_string.h functions manually builds these structures,
  48  *      then they must enforce this invariant.
  49  *
  50  *      Note that an @c svn_string(buf)_t may contain binary data,
  51  *      which means that strlen(s->data) does not have to equal @c
  52  *      s->len. The NULL terminator is provided to make it easier to
  53  *      pass @c s->data to C string interfaces.
  54  *
  55  *
  56  *   2. Non-NULL input:
  57  *
  58  *      All the functions assume their input data is non-NULL,
  59  *      unless otherwise documented, and may seg fault if passed
  60  *      NULL.  The input data may *contain* null bytes, of course, just
  61  *      the data pointer itself must not be NULL.
  62  */
  63
  64
  65 #ifndef SVN_STRING_H
  66 #define SVN_STRING_H
  67
  68 #include <apr.h>
  69 #include <apr_tables.h>
  70 #include <apr_pools.h>       /* APR memory pools for everyone. */
  71 #include <apr_strings.h>
  72
  73 #include "svn_types.h"
  74
  75 #ifdef __cplusplus
  76 extern "C" {
  77 #endif /* __cplusplus */
  78
  79 /**
  80  * @defgroup svn_string String handling
  81  * @{
  82  */
  83
  84 \f
  85
  86 /** A simple counted string. */
  87 typedef struct svn_string_t
  88 {
  89   const char *data; /**< pointer to the bytestring */
  90   apr_size_t len;   /**< length of bytestring */
  91 } svn_string_t;
  92
  93 /** A buffered string, capable of appending without an allocation and copy
  94  * for each append. */
  95 typedef struct svn_stringbuf_t
  96 {
  97   /** a pool from which this string was originally allocated, and is not
  98    * necessarily specific to this string.  This is used only for allocating
  99    * more memory from when the string needs to grow.
 100    */
 101   apr_pool_t *pool;
 102
 103   /** pointer to the bytestring */
 104   char *data;
 105
 106   /** length of bytestring */
 107   apr_size_t len;
 108
 109   /** total size of buffer allocated */
 110   apr_size_t blocksize;
 111 } svn_stringbuf_t;
 112
 113 \f
 114 /** svn_string_t functions.
 115  *
 116  * @defgroup svn_string_svn_string_t svn_string_t functions
 117  * @{
 118  */
 119
 120 /** Create a new bytestring containing a C string (NULL-terminated). */
 121 svn_string_t *svn_string_create(const char *cstring,
 122                                 apr_pool_t *pool);
 123
 124 /** Create a new bytestring containing a generic string of bytes
 125  * (NOT NULL-terminated) */
 126 svn_string_t *svn_string_ncreate(const char *bytes,
 127                                  apr_size_t size,
 128                                  apr_pool_t *pool);
 129
 130 /** Create a new string with the contents of the given stringbuf */
 131 svn_string_t *svn_string_create_from_buf(const svn_stringbuf_t *strbuf,
 132                                          apr_pool_t *pool);
 133
 134 /** Create a new bytestring by formatting @a cstring (NULL-terminated)
 135  * from varargs, which are as appropriate for apr_psprintf().
 136  */
 137 svn_string_t *svn_string_createf(apr_pool_t *pool,
 138                                  const char *fmt,
 139                                  ...)
 140   __attribute__((format(printf, 2, 3)));
 141
 142 /** Create a new bytestring by formatting @a cstring (NULL-terminated)
 143  * from a @c va_list (see svn_stringbuf_createf()).
 144  */
 145 svn_string_t *svn_string_createv(apr_pool_t *pool,
 146                                  const char *fmt,
 147                                  va_list ap)
 148   __attribute__((format(printf, 2, 0)));
 149
 150 /** Return TRUE if a bytestring is empty (has length zero). */
 151 svn_boolean_t svn_string_isempty(const svn_string_t *str);
 152
 153 /** Return a duplicate of @a original_string. */
 154 svn_string_t *svn_string_dup(const svn_string_t *original_string,
 155                              apr_pool_t *pool);
 156
 157 /** Return @c TRUE iff @a str1 and @a str2 have identical length and data. */
 158 svn_boolean_t svn_string_compare(const svn_string_t *str1,
 159                                  const svn_string_t *str2);
 160
 161 /** Return offset of first non-whitespace character in @a str, or return
 162  * @a str->len if none.
 163  */
 164 apr_size_t svn_string_first_non_whitespace(const svn_string_t *str);
 165
 166 /** Return position of last occurrence of @a ch in @a str, or return
 167  * @a str->len if no occurrence.
 168  */
 169 apr_size_t svn_string_find_char_backward(const svn_string_t *str, char ch);
 170
 171 /** @} */
 172
 173 \f
 174 /** svn_stringbuf_t functions.
 175  *
 176  * @defgroup svn_string_svn_stringbuf_t svn_stringbuf_t functions
 177  * @{
 178  */
 179
 180 /** Create a new bytestring containing a C string (NULL-terminated). */
 181 svn_stringbuf_t *svn_stringbuf_create(const char *cstring,
 182                                       apr_pool_t *pool);
 183 /** Create a new bytestring containing a generic string of bytes
 184  * (NON-NULL-terminated)
 185  */
 186 svn_stringbuf_t *svn_stringbuf_ncreate(const char *bytes,
 187                                        apr_size_t size,
 188                                        apr_pool_t *pool);
 189
 190 /** Create a new stringbuf with the contents of the given string */
 191 svn_stringbuf_t *svn_stringbuf_create_from_string(const svn_string_t *str,
 192                                                   apr_pool_t *pool);
 193
 194 /** Create a new bytestring by formatting @a cstring (NULL-terminated)
 195  * from varargs, which are as appropriate for apr_psprintf().
 196  */
 197 svn_stringbuf_t *svn_stringbuf_createf(apr_pool_t *pool,
 198                                        const char *fmt,
 199                                        ...)
 200   __attribute__((format(printf, 2, 3)));
 201
 202 /** Create a new bytestring by formatting @a cstring (NULL-terminated)
 203  * from a @c va_list (see svn_stringbuf_createf()).
 204  */
 205 svn_stringbuf_t *svn_stringbuf_createv(apr_pool_t *pool,
 206                                        const char *fmt,
 207                                        va_list ap)
 208   __attribute__((format(printf, 2, 0)));
 209
 210 /** Make sure that the string @a str has at least @a minimum_size bytes of
 211  * space available in the memory block.
 212  *
 213  * (@a minimum_size should include space for the terminating NULL character.)
 214  */
 215 void svn_stringbuf_ensure(svn_stringbuf_t *str,
 216                           apr_size_t minimum_size);
 217
 218 /** Set a bytestring @a str to @a value */
 219 void svn_stringbuf_set(svn_stringbuf_t *str, const char *value);
 220
 221 /** Set a bytestring @a str to empty (0 length). */
 222 void svn_stringbuf_setempty(svn_stringbuf_t *str);
 223
 224 /** Return @c TRUE if a bytestring is empty (has length zero). */
 225 svn_boolean_t svn_stringbuf_isempty(const svn_stringbuf_t *str);
 226
 227 /** Chop @a nbytes bytes off end of @a str, but not more than @a str->len. */
 228 void svn_stringbuf_chop(svn_stringbuf_t *str, apr_size_t nbytes);
 229
 230 /** Fill bytestring @a str with character @a c. */
 231 void svn_stringbuf_fillchar(svn_stringbuf_t *str, unsigned char c);
 232
 233 /** Append an array of bytes onto @a targetstr.
 234  *
 235  * reallocs if necessary. @a targetstr is affected, nothing else is.
 236  */
 237 void svn_stringbuf_appendbytes(svn_stringbuf_t *targetstr,
 238                                const char *bytes,
 239                                apr_size_t count);
 240
 241 /** Append an @c svn_stringbuf_t onto @a targetstr.
 242  *
 243  * reallocs if necessary. @a targetstr is affected, nothing else is.
 244  */
 245 void svn_stringbuf_appendstr(svn_stringbuf_t *targetstr,
 246                              const svn_stringbuf_t *appendstr);
 247
 248 /** Append a C string onto @a targetstr.
 249  *
 250  * reallocs if necessary. @a targetstr is affected, nothing else is.
 251  */
 252 void svn_stringbuf_appendcstr(svn_stringbuf_t *targetstr,
 253                               const char *cstr);
 254
 255 /** Return a duplicate of @a original_string. */
 256 svn_stringbuf_t *svn_stringbuf_dup(const svn_stringbuf_t *original_string,
 257                                    apr_pool_t *pool);
 258
 259
 260 /** Return @c TRUE iff @a str1 and @a str2 have identical length and data. */
 261 svn_boolean_t svn_stringbuf_compare(const svn_stringbuf_t *str1,
 262                                     const svn_stringbuf_t *str2);
 263
 264 /** Return offset of first non-whitespace character in @a str, or return
 265  * @a str->len if none.
 266  */
 267 apr_size_t svn_stringbuf_first_non_whitespace(const svn_stringbuf_t *str);
 268
 269 /** Strip whitespace from both sides of @a str (modified in place). */
 270 void svn_stringbuf_strip_whitespace(svn_stringbuf_t *str);
 271
 272 /** Return position of last occurrence of @a ch in @a str, or return
 273  * @a str->len if no occurrence.
 274  */
 275 apr_size_t svn_stringbuf_find_char_backward(const svn_stringbuf_t *str,
 276                                             char ch);
 277
 278 /** Return @c TRUE iff @a str1 and @a str2 have identical length and data. */
 279 svn_boolean_t svn_string_compare_stringbuf(const svn_string_t *str1,
 280                                            const svn_stringbuf_t *str2);
 281
 282 /** @} */
 283
 284 \f
 285 /** C strings.
 286  *
 287  * @defgroup svn_string_cstrings c string functions
 288  * @{
 289  */
 290
 291 /** Divide @a input into substrings along @a sep_chars boundaries, return an
 292  * array of copies of those substrings, allocating both the array and
 293  * the copies in @a pool.
 294  *
 295  * None of the elements added to the array contain any of the
 296  * characters in @a sep_chars, and none of the new elements are empty
 297  * (thus, it is possible that the returned array will have length
 298  * zero).
 299  *
 300  * If @a chop_whitespace is TRUE, then remove leading and trailing
 301  * whitespace from the returned strings.
 302  */
 303 apr_array_header_t *svn_cstring_split(const char *input,
 304                                       const char *sep_chars,
 305                                       svn_boolean_t chop_whitespace,
 306                                       apr_pool_t *pool);
 307
 308 /** Like svn_cstring_split(), but append to existing @a array instead of
 309  * creating a new one.  Allocate the copied substrings in @a pool
 310  * (i.e., caller decides whether or not to pass @a array->pool as @a pool).
 311  */
 312 void svn_cstring_split_append(apr_array_header_t *array,
 313                               const char *input,
 314                               const char *sep_chars,
 315                               svn_boolean_t chop_whitespace,
 316                               apr_pool_t *pool);
 317
 318
 319 /** Return @c TRUE iff @a str matches any of the elements of @a list, a list
 320  * of zero or more glob patterns.
 321  */
 322 svn_boolean_t svn_cstring_match_glob_list(const char *str,
 323                                           apr_array_header_t *list);
 324
 325 /**
 326  * Return the number of line breaks in @a msg, allowing any kind of newline
 327  * termination (CR, LF, CRLF, or LFCR), even inconsistent.
 328  *
 329  * @since New in 1.2.
 330  */
 331 int svn_cstring_count_newlines(const char *msg);
 332
 333 /**
 334  * Return a cstring which is the concatenation of @a strings (an array
 335  * of char *) each followed by @a separator (that is, @a separator
 336  * will also end the resulting string).  Allocate the result in @a pool.
 337  * If @a strings is empty, then return the empty string.
 338  *
 339  * @since New in 1.2.
 340  */
 341 char *
 342 svn_cstring_join(apr_array_header_t *strings,
 343                  const char *separator,
 344                  apr_pool_t *pool);
 345
 346 /** @} */
 347
 348 /** @} */
 349
 350 \f
 351 #ifdef __cplusplus
 352 }
 353 #endif /* __cplusplus */
 354
 355 #endif  /* SVN_STRING_H */