#ifndef STRBUF_H #define STRBUF_H /** * strbuf's are meant to be used with all the usual C string and memory * APIs. Given that the length of the buffer is known, it's often better to * use the mem* functions than a str* one (memchr vs. strchr e.g.). * Though, one has to be careful about the fact that str* functions often * stop on NULs and that strbufs may have embedded NULs. * * A strbuf is NUL terminated for convenience, but no function in the * strbuf API actually relies on the string being free of NULs. * * strbufs have some invariants that are very important to keep in mind: * * - The `buf` member is never NULL, so it can be used in any usual C * string operations safely. strbuf's _have_ to be initialized either by * `strbuf_init()` or by `= STRBUF_INIT` before the invariants, though. * * Do *not* assume anything on what `buf` really is (e.g. if it is * allocated memory or not), use `strbuf_detach()` to unwrap a memory * buffer from its strbuf shell in a safe way. That is the sole supported * way. This will give you a malloced buffer that you can later `free()`. * * However, it is totally safe to modify anything in the string pointed by * the `buf` member, between the indices `0` and `len-1` (inclusive). * * - The `buf` member is a byte array that has at least `len + 1` bytes * allocated. The extra byte is used to store a `'\0'`, allowing the * `buf` member to be a valid C-string. Every strbuf function ensure this * invariant is preserved. * * NOTE: It is OK to "play" with the buffer directly if you work it this * way: * * strbuf_grow(sb, SOME_SIZE); <1> * strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE); * * <1> Here, the memory array starting at `sb->buf`, and of length * `strbuf_avail(sb)` is all yours, and you can be sure that * `strbuf_avail(sb)` is at least `SOME_SIZE`. * * NOTE: `SOME_OTHER_SIZE` must be smaller or equal to `strbuf_avail(sb)`. * * Doing so is safe, though if it has to be done in many places, adding the * missing API to the strbuf module is the way to go. * * WARNING: Do _not_ assume that the area that is yours is of size `alloc * - 1` even if it's true in the current implementation. Alloc is somehow a * "private" member that should not be messed with. Use `strbuf_avail()` * instead. */ /** * Data Structures * --------------- */ /** * This is the string buffer structure. The `len` member can be used to * determine the current length of the string, and `buf` member provides * access to the string itself. */ struct strbuf { size_t alloc; size_t len; char *buf; }; extern char strbuf_slopbuf[]; #define STRBUF_INIT { 0, 0, strbuf_slopbuf } /** * Life Cycle Functions * -------------------- */ /** * Initialize the structure. The second parameter can be zero or a bigger * number to allocate memory, in case you want to prevent further reallocs. */ extern void strbuf_init(struct strbuf *, size_t); /** * Release a string buffer and the memory it used. You should not use the * string buffer after using this function, unless you initialize it again. */ extern void strbuf_release(struct strbuf *); /** * Detach the string from the strbuf and returns it; you now own the * storage the string occupies and it is your responsibility from then on * to release it with `free(3)` when you are done with it. */ extern char *strbuf_detach(struct strbuf *, size_t *); /** * Attach a string to a buffer. You should specify the string to attach, * the current length of the string and the amount of allocated memory. * The amount must be larger than the string length, because the string you * pass is supposed to be a NUL-terminated string. This string _must_ be * malloc()ed, and after attaching, the pointer cannot be relied upon * anymore, and neither be free()d directly. */ extern void strbuf_attach(struct strbuf *, void *, size_t, size_t); /** * Swap the contents of two string buffers. */ static inline void strbuf_swap(struct strbuf *a, struct strbuf *b) { struct strbuf tmp = *a; *a = *b; *b = tmp; } /** * Functions related to the size of the buffer * ------------------------------------------- */ /** * Determine the amount of allocated but unused memory. */ static inline size_t strbuf_avail(const struct strbuf *sb) { return sb->alloc ? sb->alloc - sb->len - 1 : 0; } /** * Ensure that at least this amount of unused memory is available after * `len`. This is used when you know a typical size for what you will add * and want to avoid repetitive automatic resizing of the underlying buffer. * This is never a needed operation, but can be critical for performance in * some cases. */ extern void strbuf_grow(struct strbuf *, size_t); /** * Set the length of the buffer to a given value. This function does *not* * allocate new memory, so you should not perform a `strbuf_setlen()` to a * length that is larger than `len + strbuf_avail()`. `strbuf_setlen()` is * just meant as a 'please fix invariants from this strbuf I just messed * with'. */ static inline void strbuf_setlen(struct strbuf *sb, size_t len) { if (len > (sb->alloc ? sb->alloc - 1 : 0)) die("BUG: strbuf_setlen() beyond buffer"); sb->len = len; sb->buf[len] = '\0'; } /** * Empty the buffer by setting the size of it to zero. */ #define strbuf_reset(sb) strbuf_setlen(sb, 0) /** * Functions related to the contents of the buffer * ----------------------------------------------- */ /** * Strip whitespace from the beginning (`ltrim`), end (`rtrim`), or both side * (`trim`) of a string. */ extern void strbuf_trim(struct strbuf *); extern void strbuf_rtrim(struct strbuf *); extern void strbuf_ltrim(struct strbuf *); /** * Replace the contents of the strbuf with a reencoded form. Returns -1 * on error, 0 on success. */ extern int strbuf_reencode(struct strbuf *sb, const char *from, const char *to); /** * Lowercase each character in the buffer using `tolower`. */ extern void strbuf_tolower(struct strbuf *sb); /** * Compare two buffers. Returns an integer less than, equal to, or greater * than zero if the first buffer is found, respectively, to be less than, * to match, or be greater than the second buffer. */ extern int strbuf_cmp(const struct strbuf *, const struct strbuf *); /** * Adding data to the buffer * ------------------------- * * NOTE: All of the functions in this section will grow the buffer as * necessary. If they fail for some reason other than memory shortage and the * buffer hadn't been allocated before (i.e. the `struct strbuf` was set to * `STRBUF_INIT`), then they will free() it. */ /** * Add a single character to the buffer. */ static inline void strbuf_addch(struct strbuf *sb, int c) { if (!strbuf_avail(sb)) strbuf_grow(sb, 1); sb->buf[sb->len++] = c; sb->buf[sb->len] = '\0'; } /** * Add a character the specified number of times to the buffer. */ extern void strbuf_addchars(struct strbuf *sb, int c, size_t n); /** * Insert data to the given position of the buffer. The remaining contents * will be shifted, not overwritten. */ extern void strbuf_insert(struct strbuf *, size_t pos, const void *, size_t); /** * Remove given amount of data from a given position of the buffer. */ extern void strbuf_remove(struct strbuf *, size_t pos, size_t len); /** * Remove the bytes between `pos..pos+len` and replace it with the given * data. */ extern void strbuf_splice(struct strbuf *, size_t pos, size_t len, const void *, size_t); /** * Add a NUL-terminated string to the buffer. Each line will be prepended * by a comment character and a blank. */ extern void strbuf_add_commented_lines(struct strbuf *out, const char *buf, size_t size); /** * Add data of given length to the buffer. */ extern void strbuf_add(struct strbuf *, const void *, size_t); /** * Add a NUL-terminated string to the buffer. * * NOTE: This function will *always* be implemented as an inline or a macro * using strlen, meaning that this is efficient to write things like: * * strbuf_addstr(sb, "immediate string"); * */ static inline void strbuf_addstr(struct strbuf *sb, const char *s) { strbuf_add(sb, s, strlen(s)); } /** * Copy the contents of another buffer at the end of the current one. */ extern void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2); /** * Copy part of the buffer from a given position till a given length to the * end of the buffer. */ extern void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len); /** * This function can be used to expand a format string containing * placeholders. To that end, it parses the string and calls the specified * function for every percent sign found. * * The callback function is given a pointer to the character after the `%` * and a pointer to the struct strbuf. It is expected to add the expanded * version of the placeholder to the strbuf, e.g. to add a newline * character if the letter `n` appears after a `%`. The function returns * the length of the placeholder recognized and `strbuf_expand()` skips * over it. * * The format `%%` is automatically expanded to a single `%` as a quoting * mechanism; callers do not need to handle the `%` placeholder themselves, * and the callback function will not be invoked for this placeholder. * * All other characters (non-percent and not skipped ones) are copied * verbatim to the strbuf. If the callback returned zero, meaning that the * placeholder is unknown, then the percent sign is copied, too. * * In order to facilitate caching and to make it possible to give * parameters to the callback, `strbuf_expand()` passes a context pointer, * which can be used by the programmer of the callback as she sees fit. */ typedef size_t (*expand_fn_t) (struct strbuf *sb, const char *placeholder, void *context); extern void strbuf_expand(struct strbuf *sb, const char *format, expand_fn_t fn, void *context); /** * Used as callback for `strbuf_expand()`, expects an array of * struct strbuf_expand_dict_entry as context, i.e. pairs of * placeholder and replacement string. The array needs to be * terminated by an entry with placeholder set to NULL. */ struct strbuf_expand_dict_entry { const char *placeholder; const char *value; }; extern size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder, void *context); /** * Append the contents of one strbuf to another, quoting any * percent signs ("%") into double-percents ("%%") in the * destination. This is useful for literal data to be fed to either * strbuf_expand or to the *printf family of functions. */ extern void strbuf_addbuf_percentquote(struct strbuf *dst, const struct strbuf *src); /** * Append the given byte size as a human-readable string (i.e. 12.23 KiB, * 3.50 MiB). */ extern void strbuf_humanise_bytes(struct strbuf *buf, off_t bytes); /** * Add a formatted string to the buffer. */ __attribute__((format (printf,2,3))) extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...); /** * Add a formatted string prepended by a comment character and a * blank to the buffer. */ __attribute__((format (printf, 2, 3))) extern void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...); __attribute__((format (printf,2,0))) extern void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap); /** * Add the time specified by `tm`, as formatted by `strftime`. */ extern void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm); /** * Read a given size of data from a FILE* pointer to the buffer. * * NOTE: The buffer is rewound if the read fails. If -1 is returned, * `errno` must be consulted, like you would do for `read(3)`. * `strbuf_read()`, `strbuf_read_file()` and `strbuf_getline_*()` * family of functions have the same behaviour as well. */ extern size_t strbuf_fread(struct strbuf *, size_t, FILE *); /** * Read the contents of a given file descriptor. The third argument can be * used to give a hint about the file size, to avoid reallocs. If read fails, * any partial read is undone. */ extern ssize_t strbuf_read(struct strbuf *, int fd, size_t hint); /** * Read the contents of a given file descriptor partially by using only one * attempt of xread. The third argument can be used to give a hint about the * file size, to avoid reallocs. Returns the number of new bytes appended to * the sb. */ extern ssize_t strbuf_read_once(struct strbuf *, int fd, size_t hint); /** * Read the contents of a file, specified by its path. The third argument * can be used to give a hint about the file size, to avoid reallocs. * Return the number of bytes read or a negative value if some error * occurred while opening or reading the file. */ extern ssize_t strbuf_read_file(struct strbuf *sb, const char *path, size_t hint); /** * Read the target of a symbolic link, specified by its path. The third * argument can be used to give a hint about the size, to avoid reallocs. */ extern int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint); /** * Write the whole content of the strbuf to the stream not stopping at * NUL bytes. */ extern ssize_t strbuf_write(struct strbuf *sb, FILE *stream); /** * Read a line from a FILE *, overwriting the existing contents of * the strbuf. The strbuf_getline*() family of functions share * this signature, but have different line termination conventions. * * Reading stops after the terminator or at EOF. The terminator * is removed from the buffer before returning. Returns 0 unless * there was nothing left before EOF, in which case it returns `EOF`. */ typedef int (*strbuf_getline_fn)(struct strbuf *, FILE *); /* Uses LF as the line terminator */ extern int strbuf_getline_lf(struct strbuf *sb, FILE *fp); /* Uses NUL as the line terminator */ extern int strbuf_getline_nul(struct strbuf *sb, FILE *fp); /* * Similar to strbuf_getline_lf(), but additionally treats a CR that * comes immediately before the LF as part of the terminator. * This is the most friendly version to be used to read "text" files * that can come from platforms whose native text format is CRLF * terminated. */ extern int strbuf_getline(struct strbuf *, FILE *); /** * Like `strbuf_getline`, but keeps the trailing terminator (if * any) in the buffer. */ extern int strbuf_getwholeline(struct strbuf *, FILE *, int); /** * Like `strbuf_getwholeline`, but operates on a file descriptor. * It reads one character at a time, so it is very slow. Do not * use it unless you need the correct position in the file * descriptor. */ extern int strbuf_getwholeline_fd(struct strbuf *, int, int); /** * Set the buffer to the path of the current working directory. */ extern int strbuf_getcwd(struct strbuf *sb); /** * Add a path to a buffer, converting a relative path to an * absolute one in the process. Symbolic links are not * resolved. */ extern void strbuf_add_absolute_path(struct strbuf *sb, const char *path); /** * Strip whitespace from a buffer. The second parameter controls if * comments are considered contents to be removed or not. */ extern void strbuf_stripspace(struct strbuf *buf, int skip_comments); /** * Temporary alias until all topic branches have switched to use * strbuf_stripspace directly. */ static inline void stripspace(struct strbuf *buf, int skip_comments) { strbuf_stripspace(buf, skip_comments); } static inline int strbuf_strip_suffix(struct strbuf *sb, const char *suffix) { if (strip_suffix_mem(sb->buf, &sb->len, suffix)) { strbuf_setlen(sb, sb->len); return 1; } else return 0; } /** * Split str (of length slen) at the specified terminator character. * Return a null-terminated array of pointers to strbuf objects * holding the substrings. The substrings include the terminator, * except for the last substring, which might be unterminated if the * original string did not end with a terminator. If max is positive, * then split the string into at most max substrings (with the last * substring containing everything following the (max-1)th terminator * character). * * The most generic form is `strbuf_split_buf`, which takes an arbitrary * pointer/len buffer. The `_str` variant takes a NUL-terminated string, * the `_max` variant takes a strbuf, and just `strbuf_split` is a convenience * wrapper to drop the `max` parameter. * * For lighter-weight alternatives, see string_list_split() and * string_list_split_in_place(). */ extern struct strbuf **strbuf_split_buf(const char *, size_t, int terminator, int max); static inline struct strbuf **strbuf_split_str(const char *str, int terminator, int max) { return strbuf_split_buf(str, strlen(str), terminator, max); } static inline struct strbuf **strbuf_split_max(const struct strbuf *sb, int terminator, int max) { return strbuf_split_buf(sb->buf, sb->len, terminator, max); } static inline struct strbuf **strbuf_split(const struct strbuf *sb, int terminator) { return strbuf_split_max(sb, terminator, 0); } /** * Free a NULL-terminated list of strbufs (for example, the return * values of the strbuf_split*() functions). */ extern void strbuf_list_free(struct strbuf **); /** * Add the abbreviation, as generated by find_unique_abbrev, of `sha1` to * the strbuf `sb`. */ extern void strbuf_add_unique_abbrev(struct strbuf *sb, const unsigned char *sha1, int abbrev_len); /** * Launch the user preferred editor to edit a file and fill the buffer * with the file's contents upon the user completing their editing. The * third argument can be used to set the environment which the editor is * run in. If the buffer is NULL the editor is launched as usual but the * file's contents are not read into the buffer upon completion. */ extern int launch_editor(const char *path, struct strbuf *buffer, const char *const *env); extern void strbuf_add_lines(struct strbuf *sb, const char *prefix, const char *buf, size_t size); /** * Append s to sb, with the characters '<', '>', '&' and '"' converted * into XML entities. */ extern void strbuf_addstr_xml_quoted(struct strbuf *sb, const char *s); /** * "Complete" the contents of `sb` by ensuring that either it ends with the * character `term`, or it is empty. This can be used, for example, * to ensure that text ends with a newline, but without creating an empty * blank line if there is no content in the first place. */ static inline void strbuf_complete(struct strbuf *sb, char term) { if (sb->len && sb->buf[sb->len - 1] != term) strbuf_addch(sb, term); } static inline void strbuf_complete_line(struct strbuf *sb) { strbuf_complete(sb, '\n'); } extern int strbuf_branchname(struct strbuf *sb, const char *name); extern int strbuf_check_branch_ref(struct strbuf *sb, const char *name); extern void strbuf_addstr_urlencode(struct strbuf *, const char *, int reserved); __attribute__((format (printf,1,2))) extern int printf_ln(const char *fmt, ...); __attribute__((format (printf,2,3))) extern int fprintf_ln(FILE *fp, const char *fmt, ...); char *xstrdup_tolower(const char *); /** * Create a newly allocated string using printf format. You can do this easily * with a strbuf, but this provides a shortcut to save a few lines. */ __attribute__((format (printf, 1, 0))) char *xstrvfmt(const char *fmt, va_list ap); __attribute__((format (printf, 1, 2))) char *xstrfmt(const char *fmt, ...); #endif /* STRBUF_H */