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-rw-r--r--util-src/ringbuffer.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/util-src/ringbuffer.c b/util-src/ringbuffer.c
index 8d9e49e6..10fe0209 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 occurence 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);