Merge branch 'mh/strbuf-split'

Cleanups and documentation for strbuf_split.

* mh/strbuf-split:
  strbuf_split*(): document functions
  strbuf_split*(): rename "delim" parameter to "terminator"
  strbuf_split_buf(): simplify iteration
  strbuf_split_buf(): use ALLOC_GROW()

3 files changed, 74 insertions, 29 deletions

diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt
index 95a8bf3846..84686b5c69 100644
--- a/Documentation/technical/api-strbuf.txt
+++ b/Documentation/technical/api-strbuf.txt
@@ -279,6 +279,22 @@ same behaviour as well.
 	Strip whitespace from a buffer. The second parameter controls if
 	comments are considered contents to be removed or not.
 
+`strbuf_split_buf`::
+`strbuf_split_str`::
+`strbuf_split_max`::
+`strbuf_split`::
+
+	Split a string or strbuf into a list of strbufs at a specified
+	terminator character.  The returned substrings include the
+	terminator characters.  Some of these functions take a `max`
+	parameter, which, if positive, limits the output to that
+	number of substrings.
+
+`strbuf_list_free`::
+
+	Free a list of strbufs (for example, the return values of the
+	`strbuf_split()` functions).
+
 `launch_editor`::
 
 	Launch the user preferred editor to edit a file and fill the buffer
diff --git a/strbuf.c b/strbuf.c
index 4b9e30cadc..05d0693eba 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -106,35 +106,30 @@ void strbuf_ltrim(struct strbuf *sb)
 	sb->buf[sb->len] = '\0';
 }
 
-struct strbuf **strbuf_split_buf(const char *str, size_t slen, int delim, int max)
+struct strbuf **strbuf_split_buf(const char *str, size_t slen,
+				 int terminator, int max)
 {
-	int alloc = 2, pos = 0;
-	const char *n, *p;
-	struct strbuf **ret;
+	struct strbuf **ret = NULL;
+	size_t nr = 0, alloc = 0;
 	struct strbuf *t;
 
-	ret = xcalloc(alloc, sizeof(struct strbuf *));
-	p = n = str;
-	while (n < str + slen) {
-		int len;
-		if (max <= 0 || pos + 1 < max)
-			n = memchr(n, delim, slen - (n - str));
-		else
-			n = NULL;
-		if (pos + 1 >= alloc) {
-			alloc = alloc * 2;
-			ret = xrealloc(ret, sizeof(struct strbuf *) * alloc);
+	while (slen) {
+		int len = slen;
+		if (max <= 0 || nr + 1 < max) {
+			const char *end = memchr(str, terminator, slen);
+			if (end)
+				len = end - str + 1;
 		}
-		if (!n)
-			n = str + slen - 1;
-		len = n - p + 1;
 		t = xmalloc(sizeof(struct strbuf));
 		strbuf_init(t, len);
-		strbuf_add(t, p, len);
-		ret[pos] = t;
-		ret[++pos] = NULL;
-		p = ++n;
+		strbuf_add(t, str, len);
+		ALLOC_GROW(ret, nr + 2, alloc);
+		ret[nr++] = t;
+		str += len;
+		slen -= len;
 	}
+	ALLOC_GROW(ret, nr + 1, alloc); /* In case string was empty */
+	ret[nr] = NULL;
 	return ret;
 }
 
diff --git a/strbuf.h b/strbuf.h
index be941ee481..aa386c6074 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -44,22 +44,56 @@ extern void strbuf_rtrim(struct strbuf *);
 extern void strbuf_ltrim(struct strbuf *);
 extern int strbuf_cmp(const struct strbuf *, const struct strbuf *);
 
+/*
+ * Split str (of length slen) at the specified terminator character.
+ * Return a null-terminated array of pointers to strbuf objects
+ * holding the substrings.  The substrings include the terminator,
+ * except for the last substring, which might be unterminated if the
+ * original string did not end with a terminator.  If max is positive,
+ * then split the string into at most max substrings (with the last
+ * substring containing everything following the (max-1)th terminator
+ * character).
+ *
+ * For lighter-weight alternatives, see string_list_split() and
+ * string_list_split_in_place().
+ */
 extern struct strbuf **strbuf_split_buf(const char *, size_t,
-					int delim, int max);
+					int terminator, int max);
+
+/*
+ * Split a NUL-terminated string at the specified terminator
+ * character.  See strbuf_split_buf() for more information.
+ */
 static inline struct strbuf **strbuf_split_str(const char *str,
-					       int delim, int max)
+					       int terminator, int max)
 {
-	return strbuf_split_buf(str, strlen(str), delim, max);
+	return strbuf_split_buf(str, strlen(str), terminator, max);
 }
+
+/*
+ * Split a strbuf at the specified terminator character.  See
+ * strbuf_split_buf() for more information.
+ */
 static inline struct strbuf **strbuf_split_max(const struct strbuf *sb,
-						int delim, int max)
+						int terminator, int max)
 {
-	return strbuf_split_buf(sb->buf, sb->len, delim, max);
+	return strbuf_split_buf(sb->buf, sb->len, terminator, max);
 }
-static inline struct strbuf **strbuf_split(const struct strbuf *sb, int delim)
+
+/*
+ * Split a strbuf at the specified terminator character.  See
+ * strbuf_split_buf() for more information.
+ */
+static inline struct strbuf **strbuf_split(const struct strbuf *sb,
+					   int terminator)
 {
-	return strbuf_split_max(sb, delim, 0);
+	return strbuf_split_max(sb, terminator, 0);
 }
+
+/*
+ * Free a NULL-terminated list of strbufs (for example, the return
+ * values of the strbuf_split*() functions).
+ */
 extern void strbuf_list_free(struct strbuf **);
 
 /*----- add data in your buffer -----*/