Andrew's git - gitweb.git/blob

   1#ifndef STRBUF_H
   2#define STRBUF_H
   3
   4/*
   5 * Strbuf's can be use in many ways: as a byte array, or to store arbitrary
   6 * long, overflow safe strings.
   7 *
   8 * Strbufs has some invariants that are very important to keep in mind:
   9 *
  10 * 1. the ->buf member is always malloc-ed, hence strbuf's can be used to
  11 *    build complex strings/buffers whose final size isn't easily known.
  12 *
  13 *    It is NOT legal to copy the ->buf pointer away.
  14 *    `strbuf_detach' is the operation that detachs a buffer from its shell
  15 *    while keeping the shell valid wrt its invariants.
  16 *
  17 * 2. the ->buf member is a byte array that has at least ->len + 1 bytes
  18 *    allocated. The extra byte is used to store a '\0', allowing the ->buf
  19 *    member to be a valid C-string. Every strbuf function ensure this
  20 *    invariant is preserved.
  21 *
  22 *    Note that it is OK to "play" with the buffer directly if you work it
  23 *    that way:
  24 *
  25 *    strbuf_grow(sb, SOME_SIZE);
  26 *       ... Here, the memory array starting at sb->buf, and of length
  27 *       ... strbuf_avail(sb) is all yours, and you are sure that
  28 *       ... strbuf_avail(sb) is at least SOME_SIZE.
  29 *    strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE);
  30 *
  31 *    Of course, SOME_OTHER_SIZE must be smaller or equal to strbuf_avail(sb).
  32 *
  33 *    Doing so is safe, though if it has to be done in many places, adding the
  34 *    missing API to the strbuf module is the way to go.
  35 *
  36 *    XXX: do _not_ assume that the area that is yours is of size ->alloc - 1
  37 *         even if it's true in the current implementation. Alloc is somehow a
  38 *         "private" member that should not be messed with.
  39 */
  40
  41#include <assert.h>
  42
  43extern char strbuf_slopbuf[];
  44struct strbuf {
  45        size_t alloc;
  46        size_t len;
  47        char *buf;
  48};
  49
  50#define STRBUF_INIT  { 0, 0, strbuf_slopbuf }
  51
  52/*----- strbuf life cycle -----*/
  53extern void strbuf_init(struct strbuf *, size_t);
  54extern void strbuf_release(struct strbuf *);
  55extern char *strbuf_detach(struct strbuf *, size_t *);
  56extern void strbuf_attach(struct strbuf *, void *, size_t, size_t);
  57static inline void strbuf_swap(struct strbuf *a, struct strbuf *b) {
  58        struct strbuf tmp = *a;
  59        *a = *b;
  60        *b = tmp;
  61}
  62
  63/*----- strbuf size related -----*/
  64static inline size_t strbuf_avail(const struct strbuf *sb) {
  65        return sb->alloc ? sb->alloc - sb->len - 1 : 0;
  66}
  67
  68extern void strbuf_grow(struct strbuf *, size_t);
  69
  70static inline void strbuf_setlen(struct strbuf *sb, size_t len) {
  71        if (!sb->alloc)
  72                strbuf_grow(sb, 0);
  73        assert(len < sb->alloc);
  74        sb->len = len;
  75        sb->buf[len] = '\0';
  76}
  77#define strbuf_reset(sb)  strbuf_setlen(sb, 0)
  78
  79/*----- content related -----*/
  80extern void strbuf_trim(struct strbuf *);
  81extern void strbuf_rtrim(struct strbuf *);
  82extern void strbuf_ltrim(struct strbuf *);
  83extern int strbuf_cmp(const struct strbuf *, const struct strbuf *);
  84extern void strbuf_tolower(struct strbuf *);
  85
  86extern struct strbuf **strbuf_split(const struct strbuf *, int delim);
  87extern void strbuf_list_free(struct strbuf **);
  88
  89/*----- add data in your buffer -----*/
  90static inline void strbuf_addch(struct strbuf *sb, int c) {
  91        strbuf_grow(sb, 1);
  92        sb->buf[sb->len++] = c;
  93        sb->buf[sb->len] = '\0';
  94}
  95
  96extern void strbuf_insert(struct strbuf *, size_t pos, const void *, size_t);
  97extern void strbuf_remove(struct strbuf *, size_t pos, size_t len);
  98
  99/* splice pos..pos+len with given data */
 100extern void strbuf_splice(struct strbuf *, size_t pos, size_t len,
 101                          const void *, size_t);
 102
 103extern void strbuf_add(struct strbuf *, const void *, size_t);
 104static inline void strbuf_addstr(struct strbuf *sb, const char *s) {
 105        strbuf_add(sb, s, strlen(s));
 106}
 107static inline void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2) {
 108        strbuf_add(sb, sb2->buf, sb2->len);
 109}
 110extern void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len);
 111
 112typedef size_t (*expand_fn_t) (struct strbuf *sb, const char *placeholder, void *context);
 113extern void strbuf_expand(struct strbuf *sb, const char *format, expand_fn_t fn, void *context);
 114struct strbuf_expand_dict_entry {
 115        const char *placeholder;
 116        const char *value;
 117};
 118extern size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder, void *context);
 119
 120__attribute__((format(printf,2,3)))
 121extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
 122
 123extern size_t strbuf_fread(struct strbuf *, size_t, FILE *);
 124/* XXX: if read fails, any partial read is undone */
 125extern ssize_t strbuf_read(struct strbuf *, int fd, size_t hint);
 126extern int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint);
 127extern int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint);
 128
 129extern int strbuf_getline(struct strbuf *, FILE *, int);
 130
 131extern void stripspace(struct strbuf *buf, int skip_comments);
 132extern int launch_editor(const char *path, struct strbuf *buffer, const char *const *env);
 133
 134#endif /* STRBUF_H */