#include "cache.h"#include <linux/kernel.h> int prefixcmp(const char *str, const char *prefix){	for (; ; str++, prefix++)		if (!*prefix)			return 0;		else if (*str != *prefix)			return (unsigned char)*prefix - (unsigned char)*str;} /* * Used as the default ->buf value, so that people can always assume * buf is non NULL and ->buf is NUL terminated even for a freshly * initialized strbuf. */char strbuf_slopbuf[1]; void strbuf_init(struct strbuf *sb, ssize_t hint){	sb->alloc = sb->len = 0;	sb->buf = strbuf_slopbuf;	if (hint)		strbuf_grow(sb, hint);} void strbuf_release(struct strbuf *sb){	if (sb->alloc) {		free(sb->buf);		strbuf_init(sb, 0);	}} char *strbuf_detach(struct strbuf *sb, size_t *sz){	char *res = sb->alloc ? sb->buf : NULL;	if (sz)		*sz = sb->len;	strbuf_init(sb, 0);	return res;} void strbuf_grow(struct strbuf *sb, size_t extra){	if (sb->len + extra + 1 <= sb->len)		die("you want to use way too much memory");	if (!sb->alloc)		sb->buf = NULL;	ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);} static void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,				   const void *data, size_t dlen){	if (pos + len < pos)		die("you want to use way too much memory");	if (pos > sb->len)		die("`pos' is too far after the end of the buffer");	if (pos + len > sb->len)		die("`pos + len' is too far after the end of the buffer"); 	if (dlen >= len)		strbuf_grow(sb, dlen - len);	memmove(sb->buf + pos + dlen,			sb->buf + pos + len,			sb->len - pos - len);	memcpy(sb->buf + pos, data, dlen);	strbuf_setlen(sb, sb->len + dlen - len);} void strbuf_remove(struct strbuf *sb, size_t pos, size_t len){	strbuf_splice(sb, pos, len, NULL, 0);} void strbuf_add(struct strbuf *sb, const void *data, size_t len){	strbuf_grow(sb, len);	memcpy(sb->buf + sb->len, data, len);	strbuf_setlen(sb, sb->len + len);} void strbuf_addf(struct strbuf *sb, const char *fmt, ...){	int len;	va_list ap; 	if (!strbuf_avail(sb))		strbuf_grow(sb, 64);	va_start(ap, fmt);	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);	va_end(ap);	if (len < 0)		die("your vsnprintf is broken");	if (len > strbuf_avail(sb)) {		strbuf_grow(sb, len);		va_start(ap, fmt);		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);		va_end(ap);		if (len > strbuf_avail(sb)) {			die("this should not happen, your vsnprintf is broken");		}	}	strbuf_setlen(sb, sb->len + len);} ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint){	size_t oldlen = sb->len;	size_t oldalloc = sb->alloc; 	strbuf_grow(sb, hint ? hint : 8192);	for (;;) {		ssize_t cnt; 		cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);		if (cnt < 0) {			if (oldalloc == 0)				strbuf_release(sb);			else				strbuf_setlen(sb, oldlen);			return -1;		}		if (!cnt)			break;		sb->len += cnt;		strbuf_grow(sb, 8192);	} 	sb->buf[sb->len] = '\0';	return sb->len - oldlen;}