1 #include "cache.h" 2 #include <linux/kernel.h> 3 4 int prefixcmp(const char *str, const char *prefix) 5 { 6 for (; ; str++, prefix++) 7 if (!*prefix) 8 return 0; 9 else if (*str != *prefix) 10 return (unsigned char)*prefix - (unsigned char)*str; 11 } 12 13 /* 14 * Used as the default ->buf value, so that people can always assume 15 * buf is non NULL and ->buf is NUL terminated even for a freshly 16 * initialized strbuf. 17 */ 18 char strbuf_slopbuf[1]; 19 20 void strbuf_init(struct strbuf *sb, ssize_t hint) 21 { 22 sb->alloc = sb->len = 0; 23 sb->buf = strbuf_slopbuf; 24 if (hint) 25 strbuf_grow(sb, hint); 26 } 27 28 void strbuf_release(struct strbuf *sb) 29 { 30 if (sb->alloc) { 31 zfree(&sb->buf); 32 strbuf_init(sb, 0); 33 } 34 } 35 36 char *strbuf_detach(struct strbuf *sb, size_t *sz) 37 { 38 char *res = sb->alloc ? sb->buf : NULL; 39 if (sz) 40 *sz = sb->len; 41 strbuf_init(sb, 0); 42 return res; 43 } 44 45 void strbuf_grow(struct strbuf *sb, size_t extra) 46 { 47 if (sb->len + extra + 1 <= sb->len) 48 die("you want to use way too much memory"); 49 if (!sb->alloc) 50 sb->buf = NULL; 51 ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc); 52 } 53 54 void strbuf_add(struct strbuf *sb, const void *data, size_t len) 55 { 56 strbuf_grow(sb, len); 57 memcpy(sb->buf + sb->len, data, len); 58 strbuf_setlen(sb, sb->len + len); 59 } 60 61 void strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap) 62 { 63 int len; 64 va_list ap_saved; 65 66 if (!strbuf_avail(sb)) 67 strbuf_grow(sb, 64); 68 69 va_copy(ap_saved, ap); 70 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap); 71 if (len < 0) 72 die("your vsnprintf is broken"); 73 if (len > strbuf_avail(sb)) { 74 strbuf_grow(sb, len); 75 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved); 76 va_end(ap_saved); 77 if (len > strbuf_avail(sb)) { 78 die("this should not happen, your vsnprintf is broken"); 79 } 80 } 81 strbuf_setlen(sb, sb->len + len); 82 } 83 84 void strbuf_addf(struct strbuf *sb, const char *fmt, ...) 85 { 86 va_list ap; 87 88 va_start(ap, fmt); 89 strbuf_addv(sb, fmt, ap); 90 va_end(ap); 91 } 92 93 ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint) 94 { 95 size_t oldlen = sb->len; 96 size_t oldalloc = sb->alloc; 97 98 strbuf_grow(sb, hint ? hint : 8192); 99 for (;;) { 100 ssize_t cnt; 101 102 cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1); 103 if (cnt < 0) { 104 if (oldalloc == 0) 105 strbuf_release(sb); 106 else 107 strbuf_setlen(sb, oldlen); 108 return -1; 109 } 110 if (!cnt) 111 break; 112 sb->len += cnt; 113 strbuf_grow(sb, 8192); 114 } 115 116 sb->buf[sb->len] = '\0'; 117 return sb->len - oldlen; 118 } 119