From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Fri, 3 Nov 2017 23:39:38 +0000 (+0200)
Subject: lib: Implement t_strsplit_tabescaped_inplace()
X-Git-Tag: 2.3.0.rc1~580
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7de17a595a44e61714d3fc7e55491449d38a8e62;p=thirdparty%2Fdovecot%2Fcore.git

lib: Implement t_strsplit_tabescaped_inplace()

This is a more efficient version of t_strsplit_tabescaped(), which modifies
the input string instead of duplicating it.
---

diff --git a/src/lib/strescape.c b/src/lib/strescape.c
index 0fb45cd20a..3be173291c 100644
--- a/src/lib/strescape.c
+++ b/src/lib/strescape.c
@@ -249,6 +249,50 @@ const char *t_str_tabunescape(const char *str)
 		return str_tabunescape(t_strdup_noconst(str));
 }
 
+const char *const *t_strsplit_tabescaped_inplace(char *data)
+{
+	/* @UNSAFE */
+	char **array;
+	unsigned int count, new_alloc_count, alloc_count;
+
+	if (*data == '\0')
+		return t_new(const char *, 1);
+
+	alloc_count = 32;
+	array = t_malloc_no0(sizeof(char *) * alloc_count);
+
+	array[0] = data; count = 1;
+	bool need_unescape = FALSE;
+	while ((data = strpbrk(data, "\t\001")) != NULL) {
+		/* separator or escape char found */
+		if (*data == '\001') {
+			need_unescape = TRUE;
+			data++;
+			continue;
+		}
+		if (count+1 >= alloc_count) {
+			new_alloc_count = nearest_power(alloc_count+1);
+			array = p_realloc(unsafe_data_stack_pool, array,
+					  sizeof(char *) * alloc_count,
+					  sizeof(char *) *
+					  new_alloc_count);
+			alloc_count = new_alloc_count;
+		}
+		*data++ = '\0';
+		if (need_unescape) {
+			str_tabunescape(array[count-1]);
+			need_unescape = FALSE;
+		}
+		array[count++] = data;
+	}
+	if (need_unescape)
+		str_tabunescape(array[count-1]);
+	i_assert(count < alloc_count);
+	array[count] = NULL;
+
+	return (const char *const *)array;
+}
+
 char **p_strsplit_tabescaped(pool_t pool, const char *str)
 {
 	char **args;
diff --git a/src/lib/strescape.h b/src/lib/strescape.h
index acf7cba67d..c910a26825 100644
--- a/src/lib/strescape.h
+++ b/src/lib/strescape.h
@@ -28,5 +28,8 @@ const char *t_str_tabunescape(const char *str);
 
 char **p_strsplit_tabescaped(pool_t pool, const char *str);
 const char *const *t_strsplit_tabescaped(const char *str);
+/* Same as t_strsplit_tabescaped(), but the input string is modified and the
+   returned pointers inside the array point to the original string. */
+const char *const *t_strsplit_tabescaped_inplace(char *str);
 
 #endif
diff --git a/src/lib/test-strescape.c b/src/lib/test-strescape.c
index 2314956e43..07c52476b3 100644
--- a/src/lib/test-strescape.c
+++ b/src/lib/test-strescape.c
@@ -155,6 +155,20 @@ static void test_strsplit_tabescaped(void)
 	test_end();
 }
 
+static void test_strsplit_tabescaped_inplace(void)
+{
+	const char *const *args;
+
+	test_begin("*_strsplit_tabescaped_inplace()");
+	for (unsigned int i = 0; i < N_ELEMENTS(strsplit_tests); i++) {
+		char *input = t_strdup_noconst(strsplit_tests[i].input);
+		args = t_strsplit_tabescaped_inplace(input);
+		for (unsigned int j = 0; strsplit_tests[i].output[j] != NULL; j++)
+			test_assert_idx(null_strcmp(strsplit_tests[i].output[j], args[j]) == 0, i);
+	}
+	test_end();
+}
+
 void test_strescape(void)
 {
 	strsplit_tests[0].input = t_strdup_printf("%s\t%s\t%s\t",
@@ -162,4 +176,5 @@ void test_strescape(void)
 	test_str_escape();
 	test_tabescape();
 	test_strsplit_tabescaped();
+	test_strsplit_tabescaped_inplace();
 }