[PATCH] New strbuf APIs: splice and attach.
* strbuf_splice replace a portion of the buffer with another.
* strbuf_attach replace a strbuf buffer with the given one, that should be
malloc'ed. Then it enforces strbuf's invariants. If alloc > len, then this
function has negligible cost, else it will perform a realloc, possibly
with a cost.
Also some style issues are fixed now.
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
---
strbuf.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++-------------
strbuf.h | 5 ++++
2 files changed, 57 insertions(+), 15 deletions(-)
diff --git a/strbuf.c b/strbuf.c
index d919047..ff551ac 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,30 +1,45 @@
#include "cache.h"
#include "strbuf.h"
-void strbuf_init(struct strbuf *sb, size_t hint) {
+void strbuf_init(struct strbuf *sb, size_t hint)
+{
memset(sb, 0, sizeof(*sb));
if (hint)
strbuf_grow(sb, hint);
}
-void strbuf_release(struct strbuf *sb) {
+void strbuf_release(struct strbuf *sb)
+{
free(sb->buf);
memset(sb, 0, sizeof(*sb));
}
-void strbuf_reset(struct strbuf *sb) {
+void strbuf_reset(struct strbuf *sb)
+{
if (sb->len)
strbuf_setlen(sb, 0);
sb->eof = 0;
}
-char *strbuf_detach(struct strbuf *sb) {
+char *strbuf_detach(struct strbuf *sb)
+{
char *res = sb->buf;
strbuf_init(sb, 0);
return res;
}
-void strbuf_grow(struct strbuf *sb, size_t extra) {
+void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
+{
+ strbuf_release(sb);
+ sb->buf = buf;
+ sb->len = len;
+ sb->alloc = alloc;
+ strbuf_grow(sb, 0);
+ sb->buf[sb->len] = '\0';
+}
+
+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");
ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
@@ -37,24 +52,44 @@ void strbuf_rtrim(struct strbuf *sb)
sb->buf[sb->len] = '\0';
}
-void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len) {
+void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
+{
strbuf_grow(sb, len);
- if (pos >= sb->len) {
- pos = sb->len;
- } else {
- memmove(sb->buf + pos + len, sb->buf + pos, sb->len - pos);
- }
+ if (pos > sb->len)
+ die("`pos' is too far after the end of the buffer");
+ memmove(sb->buf + pos + len, sb->buf + pos, sb->len - pos);
memcpy(sb->buf + pos, data, len);
strbuf_setlen(sb, sb->len + len);
}
-void strbuf_add(struct strbuf *sb, const void *data, size_t len) {
+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_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, ...) {
+void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
+{
int len;
va_list ap;
@@ -76,7 +111,8 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...) {
strbuf_setlen(sb, sb->len + len);
}
-size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f) {
+size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
+{
size_t res;
strbuf_grow(sb, size);
@@ -110,7 +146,8 @@ ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
return sb->len - oldlen;
}
-void read_line(struct strbuf *sb, FILE *fp, int term) {
+void read_line(struct strbuf *sb, FILE *fp, int term)
+{
int ch;
if (feof(fp)) {
strbuf_release(sb);
diff --git a/strbuf.h b/strbuf.h
index 21fc111..f163c63 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -55,6 +55,7 @@ extern void strbuf_init(struct strbuf *, size_t);
extern void strbuf_release(struct strbuf *);
extern void strbuf_reset(struct strbuf *);
extern char *strbuf_detach(struct strbuf *);
+extern void strbuf_attach(struct strbuf *, void *, size_t, size_t);
/*----- strbuf size related -----*/
static inline size_t strbuf_avail(struct strbuf *sb) {
@@ -81,6 +82,10 @@ static inline void strbuf_addch(struct strbuf *sb, int c) {
/* inserts after pos, or appends if pos >= sb->len */
extern void strbuf_insert(struct strbuf *, size_t pos, const void *, size_t);
+/* splice pos..pos+len with given data */
+extern void strbuf_splice(struct strbuf *, size_t pos, size_t len,
+ const void *, size_t);
+
extern void strbuf_add(struct strbuf *, const void *, size_t);
static inline void strbuf_addstr(struct strbuf *sb, const char *s) {
strbuf_add(sb, s, strlen(s));
--
1.5.3.1
Pierre Habouzit <madcoder@debian.org>