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