feat(common): Add support for replace in strbuf

common/Makefile

@@ -6,7 +6,7 @@ AR       = ar
 ARFLAGS  = rcs
 
 
-OBJS     = obj/alloc.o obj/dict.o obj/error.o obj/list.o
+OBJS     = obj/alloc.o obj/dict.o obj/error.o obj/list.o obj/strbuf.o
 DEPS     = $(OBJS:%.o=%.d)
 
 -include $(DEPS)

common/src/strbuf.c

@@ -0,0 +1,33 @@
+#include <string.h>
+
+#include "strbuf.h"
+
+strbuf_t strbuf_new(void) {
+    strbuf_t buffer = list_new(char);
+    list_add(buffer, '\0');
+    return buffer;
+}
+
+strbuf_t _strbuf_replace(strbuf_t buffer, char* needle, char* replace) {
+    size_t offset = 0;
+
+    size_t needle_length = strlen(needle);
+    size_t replace_length = strlen(replace);
+
+    char* result;
+    while((result = strstr(buffer + offset, needle)) != NULL) {
+        offset = result - buffer;
+        if (replace_length == needle_length) {
+            memcpy(result, replace, replace_length);
+        } else if (replace_length > needle_length) {
+            list_ensure_space(buffer, 1, replace_length - needle_length);
+            memmove(result + replace_length, result + needle_length, strlen(buffer) - offset - needle_length + 1);
+            memcpy(result, replace, replace_length);
+        } else {
+            memcpy(result, replace, replace_length);
+            memmove(result + replace_length, result + needle_length, strlen(buffer) - offset - needle_length + 1);
+        }
+    }
+
+    return buffer;
+}

common/src/strbuf.h

@@ -7,11 +7,9 @@
 
 typedef char* strbuf_t;
 
-#define strbuf_new() list_new(char)
 #define strbuf_clear(b) { \
 	if (b == NULL) { \
 		b = strbuf_new(); \
-        list_add(b, '\0'); \
 	} else { \
 		list_header(b)->length = 1; \
 		b[0] = '\0'; \
@@ -31,4 +29,13 @@ typedef char* strbuf_t;
     list_header(b)->length += 1; \
 }
 
+#define strbuf_replace(b, n, r) { \
+    (b) = _strbuf_replace(b, n, r); \
+}
+
+strbuf_t strbuf_new(void);
+strbuf_t _strbuf_replace(strbuf_t, char*, char*);
+
+#define strbuf_free(b) list_free(b)
+
 #endif

common/src/tests.c

@@ -4,6 +4,7 @@
 
 #include "list.h"
 #include "dict.h"
+#include "strbuf.h"
 
 void test_list_add_remove_add(void) {
     int* list = list_new(int);
@@ -65,6 +66,58 @@ void test_dict_bug_duplicate_hash(void) {
     assert_streq("foo", result, "value1 doesn't match");
 }
 
+void test_strbuf_allocation(void) {
+    strbuf_t buffer = strbuf_new();
+    assert_equals(1, list_size(buffer), "no space for null byte in empty buffer");
+
+    strbuf_append(buffer, "foo");
+    assert_equals(4, list_size(buffer), "no space for null byte after first append");
+
+    strbuf_append(buffer, "bar");
+    assert_equals(7, list_size(buffer), "no space for null byte after second append");
+
+    strbuf_free(buffer);
+}
+
+void test_strbuf_replace_equal_length(void) {
+    strbuf_t buffer = strbuf_new();
+    strbuf_append(buffer, "hello foo world foo !");
+
+    strbuf_replace(buffer, "foo", "bar");
+
+    assert_streq("hello bar world bar !", buffer, "buffer doesn't match");
+    printf("%lu, %zu\n", strlen(buffer), list_size(buffer));
+    assert_equals(strlen(buffer) + 1, list_size(buffer), "allocation doesn't match");
+
+    strbuf_free(buffer);
+}
+
+void test_strbuf_replace_shorter_length(void) {
+    strbuf_t buffer = strbuf_new();
+    strbuf_append(buffer, "hello foo world foo !");
+
+    strbuf_replace(buffer, "foo", "ba");
+
+    assert_streq("hello ba world ba !", buffer, "buffer doesn't match");
+    printf("%lu, %zu\n", strlen(buffer), list_size(buffer));
+    assert_equals(strlen(buffer) + 1 + 2, list_size(buffer), "allocation doesn't match");
+
+    strbuf_free(buffer);
+}
+
+void test_strbuf_replace_greater_length(void) {
+    strbuf_t buffer = strbuf_new();
+    strbuf_append(buffer, "hello foo world foo !");
+
+    strbuf_replace(buffer, "foo", "barr");
+
+    assert_streq("hello barr world barr !", buffer, "buffer doesn't match");
+    printf("%lu, %zu\n", strlen(buffer), list_size(buffer));
+    assert_equals(strlen(buffer) - 1, list_size(buffer), "allocation doesn't match");
+
+    strbuf_free(buffer);
+}
+
 int main(void) {
     test_init();
 
@@ -73,6 +126,11 @@ int main(void) {
     test_run(test_dict_default);
     test_run(test_dict_bug_duplicate_hash);
 
+    test_run(test_strbuf_allocation);
+    test_run(test_strbuf_replace_equal_length);
+    test_run(test_strbuf_replace_shorter_length);
+    test_run(test_strbuf_replace_greater_length);
+
     if (test_results()) {
         return 0;
     } else {