[Sheepdog] [PATCH v2 3/4] sheep: add string buf candy helpers

[Liu Yuan]

From: Liu Yuan <tailai.ly at taobao.com>

This is almost taken from git. Thank git if you find it useful.

Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
---
 sheep/strbuf.c |  192 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 sheep/strbuf.h |   95 ++++++++++++++++++++++++++++
 2 files changed, 287 insertions(+), 0 deletions(-)
 create mode 100644 sheep/strbuf.c
 create mode 100644 sheep/strbuf.h

diff --git a/sheep/strbuf.c b/sheep/strbuf.c
new file mode 100644
index 0000000..1a5f855
--- /dev/null
+++ b/sheep/strbuf.c
@@ -0,0 +1,192 @@
+/* Taken from git by Liu Yuan <namei.unix at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "strbuf.h"
+#include "logger.h"
+
+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)
+{
+	free(sb->buf);
+	memset(sb, 0, sizeof(*sb));
+}
+
+void strbuf_reset(struct strbuf *sb)
+{
+	if (sb->len)
+		strbuf_setlen(sb, 0);
+	sb->eof = 0;
+}
+
+char *strbuf_detach(struct strbuf *sb)
+{
+	char *res = sb->buf;
+	strbuf_init(sb, 0);
+	return res;
+}
+
+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)
+		panic("you want to use way too much memory");
+	ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
+}
+
+void strbuf_rtrim(struct strbuf *sb)
+{
+	while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
+		sb->len--;
+	sb->buf[sb->len] = '\0';
+}
+
+void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
+{
+	strbuf_grow(sb, len);
+	if (pos > sb->len)
+		panic("`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_splice(struct strbuf *sb, size_t pos, size_t len,
+		const void *data, size_t dlen)
+{
+	if (pos + len < pos)
+		panic("you want to use way too much memory");
+	if (pos > sb->len)
+		panic("`pos' is too far after the end of the buffer");
+	if (pos + len > sb->len)
+		panic("`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;
+
+	va_start(ap, fmt);
+	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
+	va_end(ap);
+	if (len < 0) {
+		len = 0;
+	}
+	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)) {
+			panic("this should not happen, your snprintf is broken");
+		}
+	}
+	strbuf_setlen(sb, sb->len + len);
+}
+
+size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
+{
+	size_t res;
+
+	strbuf_grow(sb, size);
+	res = fread(sb->buf + sb->len, 1, size, f);
+	if (res > 0) {
+		strbuf_setlen(sb, sb->len + res);
+	}
+	return res;
+}
+
+ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
+{
+	size_t oldlen = sb->len;
+
+	strbuf_grow(sb, hint ? hint : 8192);
+	for (;;) {
+		ssize_t cnt;
+
+		cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
+		if (cnt < 0) {
+			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;
+}
+
+static int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
+{
+	int ch;
+
+	if (feof(fp))
+		return EOF;
+
+	strbuf_reset(sb);
+	while ((ch = fgetc(fp)) != EOF) {
+		strbuf_grow(sb, 1);
+		sb->buf[sb->len++] = ch;
+		if (ch == term)
+			break;
+	}
+	if (ch == EOF && sb->len == 0)
+		return EOF;
+
+	sb->buf[sb->len] = '\0';
+	return 0;
+}
+
+int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
+{
+	if (strbuf_getwholeline(sb, fp, term))
+		return EOF;
+	if (sb->buf[sb->len-1] == term)
+		strbuf_setlen(sb, sb->len-1);
+	return 0;
+}
diff --git a/sheep/strbuf.h b/sheep/strbuf.h
new file mode 100644
index 0000000..573784b
--- /dev/null
+++ b/sheep/strbuf.h
@@ -0,0 +1,95 @@
+#ifndef STRBUF_H
+#define STRBUF_H
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "util.h"
+
+struct strbuf {
+	size_t alloc;
+	size_t len;
+	int eof;
+	char *buf;
+};
+
+#define alloc_nr(x) (((x)+16)*3/2)
+
+/*
+ * Realloc the buffer pointed at by variable 'x' so that it can hold
+ * at least 'nr' entries; the number of entries currently allocated
+ * is 'alloc', using the standard growing factor alloc_nr() macro.
+ *
+ * DO NOT USE any expression with side-effect for 'x' or 'alloc'.
+ */
+#define ALLOC_GROW(x, nr, alloc) \
+	do { \
+		if ((nr) > alloc) { \
+			if (alloc_nr(alloc) < (nr)) \
+			alloc = (nr); \
+			else \
+			alloc = alloc_nr(alloc); \
+			x = xrealloc((x), alloc * sizeof(*(x))); \
+		} \
+	} while(0)
+
+#define STRBUF_INIT  { 0, 0, 0, NULL }
+
+/*----- strbuf life cycle -----*/
+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) {
+	return sb->alloc ? sb->alloc - sb->len - 1 : 0;
+}
+static inline void strbuf_setlen(struct strbuf *sb, size_t len) {
+	assert (len < sb->alloc);
+	sb->len = len;
+	sb->buf[len] = '\0';
+}
+
+extern void strbuf_grow(struct strbuf *, size_t);
+
+/*----- content related -----*/
+extern void strbuf_rtrim(struct strbuf *);
+
+/*----- add data in your buffer -----*/
+static inline void strbuf_addch(struct strbuf *sb, int c) {
+	strbuf_grow(sb, 1);
+	sb->buf[sb->len++] = c;
+	sb->buf[sb->len] = '\0';
+}
+
+/* inserts after pos, or appends if pos >= sb->len */
+extern void strbuf_insert(struct strbuf *, size_t pos, const void *, size_t);
+extern void strbuf_remove(struct strbuf *, size_t pos, size_t len);
+
+/* 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));
+}
+static inline void strbuf_addbuf(struct strbuf *sb, struct strbuf *sb2) {
+	strbuf_add(sb, sb2->buf, sb2->len);
+}
+
+__attribute__((format(printf,2,3)))
+extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...);
+
+extern size_t strbuf_fread(struct strbuf *, size_t, FILE *);
+/* XXX: if read fails, any partial read is undone */
+extern ssize_t strbuf_read(struct strbuf *, int fd, size_t hint);
+int strbuf_getline(struct strbuf *sb, FILE *fp, int term);
+
+#endif
-- 
1.7.6.1