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 legal to copy the ->buf pointer away. Though if you want to reuse 14 * the strbuf after that, setting ->buf to NULL isn't legal. 15 * `strbuf_detach' is the operation that detachs a buffer from its shell 16 * while keeping the shell valid wrt its invariants. 17 * 18 * 2. the ->buf member is a byte array that has at least ->len + 1 bytes 19 * allocated. The extra byte is used to store a '\0', allowing the ->buf 20 * member to be a valid C-string. Every strbuf function ensure this 21 * invariant is preserved. 22 * 23 * Note that it is OK to "play" with the buffer directly if you work it 24 * that way: 25 * 26 * strbuf_grow(sb, SOME_SIZE); 27 * // ... here the memory areay starting at sb->buf, and of length 28 * // sb_avail(sb) is all yours, and you are sure that sb_avail(sb) is at 29 * // least SOME_SIZE 30 * strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE); 31 * 32 * Of course, SOME_OTHER_SIZE must be smaller or equal to sb_avail(sb). 33 * 34 * Doing so is safe, though if it has to be done in many places, adding the 35 * missing API to the strbuf module is the way to go. 36 * 37 * XXX: do _not_ assume that the area that is yours is of size ->alloc - 1 38 * even if it's true in the current implementation. Alloc is somehow a 39 * "private" member that should not be messed with. 40 */ 41 42#include <assert.h> 43 44struct strbuf { 45 size_t alloc; 46 size_t len; 47 char *buf; 48}; 49 50#define STRBUF_INIT { 0, 0, NULL } 51 52/*----- strbuf life cycle -----*/ 53extern void strbuf_init(struct strbuf *, size_t); 54extern void strbuf_release(struct strbuf *); 55extern void strbuf_reset(struct strbuf *); 56extern char *strbuf_detach(struct strbuf *); 57extern void strbuf_attach(struct strbuf *, void *, size_t, size_t); 58static inline void strbuf_swap(struct strbuf *a, struct strbuf *b) { 59 struct strbuf tmp = *a; 60 *a = *b; 61 *b = tmp; 62} 63 64/*----- strbuf size related -----*/ 65static inline size_t strbuf_avail(struct strbuf *sb) { 66 return sb->alloc ? sb->alloc - sb->len - 1 : 0; 67} 68 69extern void strbuf_grow(struct strbuf *, size_t); 70 71static inline void strbuf_setlen(struct strbuf *sb, size_t len) { 72 if (!sb->alloc) 73 strbuf_grow(sb, 0); 74 assert(len < sb->alloc); 75 sb->len = len; 76 sb->buf[len] = '\0'; 77} 78 79/*----- content related -----*/ 80extern void strbuf_rtrim(struct strbuf *); 81extern int strbuf_cmp(struct strbuf *, struct strbuf *); 82 83/*----- add data in your buffer -----*/ 84static inline void strbuf_addch(struct strbuf *sb, int c) { 85 strbuf_grow(sb, 1); 86 sb->buf[sb->len++] = c; 87 sb->buf[sb->len] = '\0'; 88} 89 90extern void strbuf_insert(struct strbuf *, size_t pos, const void *, size_t); 91extern void strbuf_remove(struct strbuf *, size_t pos, size_t len); 92 93/* splice pos..pos+len with given data */ 94extern void strbuf_splice(struct strbuf *, size_t pos, size_t len, 95 const void *, size_t); 96 97extern void strbuf_add(struct strbuf *, const void *, size_t); 98static inline void strbuf_addstr(struct strbuf *sb, const char *s) { 99 strbuf_add(sb, s, strlen(s)); 100} 101static inline void strbuf_addbuf(struct strbuf *sb, struct strbuf *sb2) { 102 strbuf_add(sb, sb2->buf, sb2->len); 103} 104 105__attribute__((format(printf,2,3))) 106extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...); 107 108extern size_t strbuf_fread(struct strbuf *, size_t, FILE *); 109/* XXX: if read fails, any partial read is undone */ 110extern ssize_t strbuf_read(struct strbuf *, int fd, size_t hint); 111extern int strbuf_read_file(struct strbuf *sb, const char *path); 112 113extern int strbuf_getline(struct strbuf *, FILE *, int); 114 115extern void stripspace(struct strbuf *buf, int skip_comments); 116 117#endif /* STRBUF_H */