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Diffstat (limited to 'src/util/str.h')
-rw-r--r-- | src/util/str.h | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/src/util/str.h b/src/util/str.h new file mode 100644 index 0000000..588e6fc --- /dev/null +++ b/src/util/str.h @@ -0,0 +1,357 @@ +/* + * Copyright (C) the libgit2 contributors. All rights reserved. + * + * This file is part of libgit2, distributed under the GNU GPL v2 with + * a Linking Exception. For full terms see the included COPYING file. + */ +#ifndef INCLUDE_str_h__ +#define INCLUDE_str_h__ + +#include "git2_util.h" + +struct git_str { + char *ptr; + size_t asize; + size_t size; +}; + +typedef enum { + GIT_STR_BOM_NONE = 0, + GIT_STR_BOM_UTF8 = 1, + GIT_STR_BOM_UTF16_LE = 2, + GIT_STR_BOM_UTF16_BE = 3, + GIT_STR_BOM_UTF32_LE = 4, + GIT_STR_BOM_UTF32_BE = 5 +} git_str_bom_t; + +typedef struct { + git_str_bom_t bom; /* BOM found at head of text */ + unsigned int nul, cr, lf, crlf; /* NUL, CR, LF and CRLF counts */ + unsigned int printable, nonprintable; /* These are just approximations! */ +} git_str_text_stats; + +extern char git_str__initstr[]; +extern char git_str__oom[]; + +/* Use to initialize string buffer structure when git_str is on stack */ +#define GIT_STR_INIT { git_str__initstr, 0, 0 } + +/** + * Static initializer for git_str from static string buffer + */ +#define GIT_STR_INIT_CONST(str, len) { (char *)(str), 0, (size_t)(len) } + +GIT_INLINE(bool) git_str_is_allocated(const git_str *str) +{ + return (str->ptr != NULL && str->asize > 0); +} + +/** + * Initialize a git_str structure. + * + * For the cases where GIT_STR_INIT cannot be used to do static + * initialization. + */ +extern int git_str_init(git_str *str, size_t initial_size); + +extern void git_str_dispose(git_str *str); + +/** + * Resize the string buffer allocation to make more space. + * + * This will attempt to grow the string buffer to accommodate the target + * size. The bstring buffer's `ptr` will be replaced with a newly + * allocated block of data. Be careful so that memory allocated by the + * caller is not lost. As a special variant, if you pass `target_size` as + * 0 and the memory is not allocated by libgit2, this will allocate a new + * buffer of size `size` and copy the external data into it. + * + * Currently, this will never shrink a buffer, only expand it. + * + * If the allocation fails, this will return an error and the buffer will be + * marked as invalid for future operations, invaliding the contents. + * + * @param str The buffer to be resized; may or may not be allocated yet + * @param target_size The desired available size + * @return 0 on success, -1 on allocation failure + */ +int git_str_grow(git_str *str, size_t target_size); + +/** + * Resize the buffer allocation to make more space. + * + * This will attempt to grow the string buffer to accommodate the + * additional size. It is similar to `git_str_grow`, but performs the + * new size calculation, checking for overflow. + * + * Like `git_str_grow`, if this is a user-supplied string buffer, + * this will allocate a new string uffer. + */ +extern int git_str_grow_by(git_str *str, size_t additional_size); + +/** + * Attempt to grow the buffer to hold at least `target_size` bytes. + * + * If the allocation fails, this will return an error. If `mark_oom` is + * true, this will mark the string buffer as invalid for future + * operations; if false, existing string buffer content will be preserved, + * but calling code must handle that string buffer was not expanded. If + * `preserve_external` is true, then any existing data pointed to be + * `ptr` even if `asize` is zero will be copied into the newly allocated + * string buffer. + */ +extern int git_str_try_grow( + git_str *str, size_t target_size, bool mark_oom); + +extern void git_str_swap(git_str *str_a, git_str *str_b); +extern char *git_str_detach(git_str *str); +extern int git_str_attach(git_str *str, char *ptr, size_t asize); + +/* Populates a `git_str` where the contents are not "owned" by the string + * buffer, and calls to `git_str_dispose` will not free the given str. + */ +extern void git_str_attach_notowned( + git_str *str, const char *ptr, size_t size); + +/** + * Test if there have been any reallocation failures with this git_str. + * + * Any function that writes to a git_str can fail due to memory allocation + * issues. If one fails, the git_str will be marked with an OOM error and + * further calls to modify the string buffer will fail. Check + * git_str_oom() at the end of your sequence and it will be true if you + * ran out of memory at any point with that string buffer. + * + * @return false if no error, true if allocation error + */ +GIT_INLINE(bool) git_str_oom(const git_str *str) +{ + return (str->ptr == git_str__oom); +} + +/* + * Functions below that return int value error codes will return 0 on + * success or -1 on failure (which generally means an allocation failed). + * Using a git_str where the allocation has failed with result in -1 from + * all further calls using that string buffer. As a result, you can + * ignore the return code of these functions and call them in a series + * then just call git_str_oom at the end. + */ + +int git_str_set(git_str *str, const void *data, size_t datalen); + +int git_str_sets(git_str *str, const char *string); +int git_str_putc(git_str *str, char c); +int git_str_putcn(git_str *str, char c, size_t len); +int git_str_put(git_str *str, const char *data, size_t len); +int git_str_puts(git_str *str, const char *string); +int git_str_printf(git_str *str, const char *format, ...) GIT_FORMAT_PRINTF(2, 3); +int git_str_vprintf(git_str *str, const char *format, va_list ap); +void git_str_clear(git_str *str); +void git_str_consume_bytes(git_str *str, size_t len); +void git_str_consume(git_str *str, const char *end); +void git_str_truncate(git_str *str, size_t len); +void git_str_shorten(git_str *str, size_t amount); +void git_str_truncate_at_char(git_str *path, char separator); +void git_str_rtruncate_at_char(git_str *path, char separator); + +/** General join with separator */ +int git_str_join_n(git_str *str, char separator, int len, ...); +/** Fast join of two strings - first may legally point into `str` data */ +int git_str_join(git_str *str, char separator, const char *str_a, const char *str_b); +/** Fast join of three strings - cannot reference `str` data */ +int git_str_join3(git_str *str, char separator, const char *str_a, const char *str_b, const char *str_c); + +/** + * Join two strings as paths, inserting a slash between as needed. + * @return 0 on success, -1 on failure + */ +GIT_INLINE(int) git_str_joinpath(git_str *str, const char *a, const char *b) +{ + return git_str_join(str, '/', a, b); +} + +GIT_INLINE(const char *) git_str_cstr(const git_str *str) +{ + return str->ptr; +} + +GIT_INLINE(size_t) git_str_len(const git_str *str) +{ + return str->size; +} + +int git_str_copy_cstr(char *data, size_t datasize, const git_str *str); + +#define git_str_PUTS(str, cstr) git_str_put(str, cstr, sizeof(cstr) - 1) + +GIT_INLINE(ssize_t) git_str_rfind_next(const git_str *str, char ch) +{ + ssize_t idx = (ssize_t)str->size - 1; + while (idx >= 0 && str->ptr[idx] == ch) idx--; + while (idx >= 0 && str->ptr[idx] != ch) idx--; + return idx; +} + +GIT_INLINE(ssize_t) git_str_rfind(const git_str *str, char ch) +{ + ssize_t idx = (ssize_t)str->size - 1; + while (idx >= 0 && str->ptr[idx] != ch) idx--; + return idx; +} + +GIT_INLINE(ssize_t) git_str_find(const git_str *str, char ch) +{ + void *found = memchr(str->ptr, ch, str->size); + return found ? (ssize_t)((const char *)found - str->ptr) : -1; +} + +/* Remove whitespace from the end of the string buffer */ +void git_str_rtrim(git_str *str); + +int git_str_cmp(const git_str *a, const git_str *b); + +/* Quote and unquote a string buffer as specified in + * http://marc.info/?l=git&m=112927316408690&w=2 + */ +int git_str_quote(git_str *str); +int git_str_unquote(git_str *str); + +/* Write data as a hex string */ +int git_str_encode_hexstr(git_str *str, const char *data, size_t len); + +/* Write data as base64 encoded in string buffer */ +int git_str_encode_base64(git_str *str, const char *data, size_t len); +/* Decode the given bas64 and write the result to the string buffer */ +int git_str_decode_base64(git_str *str, const char *base64, size_t len); + +/* Write data as "base85" encoded in string buffer */ +int git_str_encode_base85(git_str *str, const char *data, size_t len); +/* Decode the given "base85" and write the result to the string buffer */ +int git_str_decode_base85(git_str *str, const char *base64, size_t len, size_t output_len); + +/* + * Decode the given percent-encoded string and write the result to the + * string buffer. + */ +int git_str_decode_percent(git_str *str, const char *encoded, size_t len); + +/* + * Insert, remove or replace a portion of the string buffer. + * + * @param str The string buffer to work with + * + * @param where The location in the string buffer where the transformation + * should be applied. + * + * @param nb_to_remove The number of chars to be removed. 0 to not + * remove any character in the string buffer. + * + * @param data A pointer to the data which should be inserted. + * + * @param nb_to_insert The number of chars to be inserted. 0 to not + * insert any character from the string buffer. + * + * @return 0 or an error code. + */ +int git_str_splice( + git_str *str, + size_t where, + size_t nb_to_remove, + const char *data, + size_t nb_to_insert); + +/** + * Append string to string buffer, prefixing each character from + * `esc_chars` with `esc_with` string. + * + * @param str String buffer to append data to + * @param string String to escape and append + * @param esc_chars Characters to be escaped + * @param esc_with String to insert in from of each found character + * @return 0 on success, <0 on failure (probably allocation problem) + */ +extern int git_str_puts_escaped( + git_str *str, + const char *string, + const char *esc_chars, + const char *esc_with); + +/** + * Append string escaping characters that are regex special + */ +GIT_INLINE(int) git_str_puts_escape_regex(git_str *str, const char *string) +{ + return git_str_puts_escaped(str, string, "^.[]$()|*+?{}\\", "\\"); +} + +/** + * Unescape all characters in a string buffer in place + * + * I.e. remove backslashes + */ +extern void git_str_unescape(git_str *str); + +/** + * Replace all \r\n with \n. + * + * @return 0 on success, -1 on memory error + */ +extern int git_str_crlf_to_lf(git_str *tgt, const git_str *src); + +/** + * Replace all \n with \r\n. Does not modify existing \r\n. + * + * @return 0 on success, -1 on memory error + */ +extern int git_str_lf_to_crlf(git_str *tgt, const git_str *src); + +/** + * Fill string buffer with the common prefix of a array of strings + * + * String buffer will be set to empty if there is no common prefix + */ +extern int git_str_common_prefix(git_str *buf, char *const *const strings, size_t count); + +/** + * Check if a string buffer begins with a UTF BOM + * + * @param bom Set to the type of BOM detected or GIT_BOM_NONE + * @param str String buffer in which to check the first bytes for a BOM + * @return Number of bytes of BOM data (or 0 if no BOM found) + */ +extern int git_str_detect_bom(git_str_bom_t *bom, const git_str *str); + +/** + * Gather stats for a piece of text + * + * Fill the `stats` structure with counts of unreadable characters, carriage + * returns, etc, so it can be used in heuristics. This automatically skips + * a trailing EOF (\032 character). Also it will look for a BOM at the + * start of the text and can be told to skip that as well. + * + * @param stats Structure to be filled in + * @param str Text to process + * @param skip_bom Exclude leading BOM from stats if true + * @return Does the string buffer heuristically look like binary data + */ +extern bool git_str_gather_text_stats( + git_str_text_stats *stats, const git_str *str, bool skip_bom); + +/** +* Check quickly if string buffer looks like it contains binary data +* +* @param str string buffer to check +* @return 1 if string buffer looks like non-text data +*/ +int git_str_is_binary(const git_str *str); + +/** +* Check quickly if buffer contains a NUL byte +* +* @param str string buffer to check +* @return 1 if string buffer contains a NUL byte +*/ +int git_str_contains_nul(const git_str *str); + +#endif |