1 files changed, 42 insertions, 0 deletions

diff --git a/util-src/ringbuffer.c b/util-src/ringbuffer.c
index 8d9e49e6..8f9013f7 100644
--- a/util-src/ringbuffer.c
+++ b/util-src/ringbuffer.c
@@ -39,10 +39,12 @@ int find(ringbuffer *b, const char *s, size_t l) {
 		return 0;
 	}
 
+	/* look for a matching first byte */
 	for(i = 0; i <= b->blen - l; i++) {
 		if(b->buffer[(b->rpos + i) % b->alen] == *s) {
 			m = 1;
 
+			/* check if the following byte also match */
 			for(j = 1; j < l; j++)
 				if(b->buffer[(b->rpos + i + j) % b->alen] != s[j]) {
 					m = 0;
@@ -58,6 +60,10 @@ int find(ringbuffer *b, const char *s, size_t l) {
 	return 0;
 }
 
+/*
+ * Find first position of a substring in buffer
+ * (buffer, string) -> number
+ */
 int rb_find(lua_State *L) {
 	size_t l, m;
 	ringbuffer *b = luaL_checkudata(L, 1, "ringbuffer_mt");
@@ -72,6 +78,31 @@ int rb_find(lua_State *L) {
 	return 0;
 }
 
+/*
+ * Move read position forward without returning the data
+ * (buffer, number) -> boolean
+ */
+int rb_discard(lua_State *L) {
+	ringbuffer *b = luaL_checkudata(L, 1, "ringbuffer_mt");
+	size_t r = luaL_checkinteger(L, 2);
+
+	if(r > b->blen) {
+		lua_pushboolean(L, 0);
+		return 1;
+	}
+
+	b->blen -= r;
+	b->rpos += r;
+	modpos(b);
+
+	lua_pushboolean(L, 1);
+	return 1;
+}
+
+/*
+ * Read bytes from buffer
+ * (buffer, number, boolean?) -> string
+ */
 int rb_read(lua_State *L) {
 	ringbuffer *b = luaL_checkudata(L, 1, "ringbuffer_mt");
 	size_t r = luaL_checkinteger(L, 2);
@@ -83,6 +114,7 @@ int rb_read(lua_State *L) {
 	}
 
 	if((b->rpos + r) > b->alen) {
+		/* Substring wraps around to the beginning of the buffer */
 		lua_pushlstring(L, &b->buffer[b->rpos], b->alen - b->rpos);
 		lua_pushlstring(L, b->buffer, r - (b->alen - b->rpos));
 		lua_concat(L, 2);
@@ -99,6 +131,10 @@ int rb_read(lua_State *L) {
 	return 1;
 }
 
+/*
+ * Read buffer until first occurrence of a substring
+ * (buffer, string) -> string
+ */
 int rb_readuntil(lua_State *L) {
 	size_t l, m;
 	ringbuffer *b = luaL_checkudata(L, 1, "ringbuffer_mt");
@@ -114,6 +150,10 @@ int rb_readuntil(lua_State *L) {
 	return 0;
 }
 
+/*
+ * Write bytes into the buffer
+ * (buffer, string) -> integer
+ */
 int rb_write(lua_State *L) {
 	size_t l, w = 0;
 	ringbuffer *b = luaL_checkudata(L, 1, "ringbuffer_mt");
@@ -191,6 +231,8 @@ int luaopen_util_ringbuffer(lua_State *L) {
 		{
 			lua_pushcfunction(L, rb_find);
 			lua_setfield(L, -2, "find");
+			lua_pushcfunction(L, rb_discard);
+			lua_setfield(L, -2, "discard");
 			lua_pushcfunction(L, rb_read);
 			lua_setfield(L, -2, "read");
 			lua_pushcfunction(L, rb_readuntil);