lib: sv: add sv_concat_cstr(), sv_init() and sv_free()

Creates an default option to heap-init string view to be used by
complex operation where memory needs to be fine-grained.

2 files changed, 64 insertions, 3 deletions

diff --git a/include/lib/sv.h b/include/lib/sv.h
index f5169d0..125939a 100644
--- a/include/lib/sv.h
+++ b/include/lib/sv.h
@@ -8,9 +8,13 @@ struct string_view {
    size_t len;
 };
 
-struct string_view sv_create(char *buf, size_t len);
+struct string_view sv_create(const char *buf, const size_t len);
+int sv_init(struct string_view *sv, const char *buf);
+void  sv_free(struct string_view *sv);
 struct string_view sv_copy(struct string_view *sv);
 int sv_equal(struct string_view *a, struct string_view *b);
+struct string_view sv_concat(struct string_view *a, struct string_view *b);
+int sv_concat_cstr(struct string_view *sv, const char *cstr);
 
 #define SV(x) (struct string_view){(x), sizeof(x) - 1}
 
diff --git a/src/lib/sv.c b/src/lib/sv.c
index 34d214f..33881d2 100644
--- a/src/lib/sv.c
+++ b/src/lib/sv.c
@@ -4,9 +4,30 @@
 #include <string.h>
 #include <assert.h>
 
-struct string_view sv_create(char *buf, size_t len)
+struct string_view sv_create(const char *buf, const size_t len)
 {
-    return (struct string_view){.buf = buf, .len = len}; 
+	return (struct string_view){.buf = buf, .len = len}; 
+}
+
+int sv_init(struct string_view *sv, const char *b)
+{
+	assert(sv != NULL);
+
+	size_t len = strlen(b);
+	void *ptr = malloc(len);
+
+	memcpy(ptr, b, len);
+
+	sv->buf = ptr;
+	sv->len = len;
+	
+	return 0;	       
+}
+
+void sv_free(struct string_view *sv)
+{
+	assert(sv != NULL);       
+	free(sv->buf);
 }
 
 /**
@@ -38,3 +59,39 @@ int sv_equal(struct string_view *a, struct string_view *b)
 
     return 1;
 }
+
+/**
+ *  @warning User's responsibility to cleanup memory.
+ */
+struct string_view sv_concat(struct string_view *a, struct string_view *b)
+{
+    assert(a != NULL);
+    assert(b != NULL);
+    size_t nlen = a->len + b->len;
+    char *ptr = malloc(nlen);
+    return (struct string_view){.buf = ptr, .len = nlen};
+}
+
+int sv_concat_cstr(struct string_view *a, const char *cstr)
+{
+	assert(a != NULL);
+
+	if (a->len > 0 && a->buf[a->len - 1] == '\0')
+		a->len--;
+
+	size_t lenb = strlen(cstr);
+	size_t nlen = lenb + a->len + 1;
+
+        char *tmp = realloc(a->buf, nlen);
+
+	if (tmp == NULL)
+		return -1;	
+
+	a->buf = tmp;
+	
+	memcpy(a->buf + a->len, cstr, lenb);
+	a->len = nlen - 1;
+	a->buf[a->len] = '\0';
+	
+	return 0;
+}