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#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.
*/
static inline void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2)
{
strbuf_grow(sb, sb2->len);
strbuf_add(sb, sb2->buf, sb2->len);
}
/**
* 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()` has 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 file, specified by its path. The third argument
* can be used to give a hint about the file size, to avoid reallocs.
*/
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);
/**
* Read a line from a FILE *, overwriting the existing contents
* of the strbuf. The second argument specifies the line
* terminator character, typically `'\n'`.
* 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`.
*/
extern int strbuf_getline(struct strbuf *, FILE *, int);
/**
* 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 stripspace(struct strbuf *buf, int 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 **);
/**
* 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);
static inline void strbuf_complete_line(struct strbuf *sb)
{
if (sb->len && sb->buf[sb->len - 1] != '\n')
strbuf_addch(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 */
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