1 files changed, 97 insertions, 0 deletions
diff --git a/buffer.c b/buffer.c
new file mode 100644
index 0000000..cadfb7d
--- /dev/null
+++ b/buffer.c
@@ -0,0 +1,97 @@
+#include "buffer.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <lua.h>
+
+#include "stream.h"
+
+void grow(lua_State * L, struct buffer * b)
+{
+	int allocated = b->allocated + 1024;
+
+	if (8192 < allocated)
+	{
+		lua_pushliteral(L, "Too large buffer");
+		lua_error(L);
+	}
+
+	void * buffer = realloc(b->data, allocated);
+
+	if (NULL == buffer)
+	{
+		lua_pushliteral(L, "Could not grow buffer");
+		lua_error(L);
+	}
+
+	b->data = buffer;
+	b->allocated = allocated;
+}
+
+int read_more(lua_State * L, struct stream * s, int minimum_length, lua_KContext ctx)
+{
+	const int free_space = s->in.allocated + s->in.offset - s->in.length - 1;
+
+	while (free_space < minimum_length)
+	{
+		grow(L, &s->in);
+	}
+
+	if (0 < s->in.offset)
+	{
+		memmove(s->in.data, s->in.data + s->in.offset, s->in.length - s->in.offset);
+		s->in.offset = 0;
+		s->in.length -= s->in.offset;
+	}
+
+	int length = read(s->fd, s->in.data + s->in.length, free_space);
+
+	if (-1 == length)
+	{
+		if (EWOULDBLOCK == errno || EAGAIN == errno)
+		{
+			return lua_yieldk(L, 0, ctx, stream_readk);
+		}
+		else
+		{
+			lua_pushstring(L, strerror(errno));
+			return lua_error(L);
+		}
+	}
+
+	s->in.length += length;
+
+	return length;
+}
+
+int prepare_at_least(lua_State * L, struct stream * s, int minimum_length, lua_KContext ctx)
+{
+	const int remaining_bytes = s->in.length - s->in.next;
+
+	if (remaining_bytes < minimum_length)
+	{
+		return read_more(L, s, minimum_length, ctx);
+	}
+
+	return remaining_bytes;
+}
+
+int until(struct buffer * b, const char * pattern, int pattern_length)
+{
+	while (b->next + pattern_length <= b->length)
+	{
+		if (0 == strncmp(&b->data[b->next], pattern, pattern_length))
+		{
+			return b->next;
+		}
+		else
+		{
+			b->next++;
+		}
+	}
+
+	return -1;
+}