add some lua library

lua-protobuf/stringpool.c

@@ -0,0 +1,60 @@
+#include "alloc.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#define PAGE_SIZE 256
+
+struct _stringpool {
+	char * buffer;
+	size_t len;
+	struct _stringpool *next;
+};
+
+struct _stringpool * 
+_pbcS_new(void) {
+	struct _stringpool * ret = (struct _stringpool *)malloc(sizeof(struct _stringpool) + PAGE_SIZE);
+	ret->buffer = (char *)(ret + 1);
+	ret->len = 0;
+	ret->next = NULL;
+	return ret;
+}
+
+void 
+_pbcS_delete(struct _stringpool *pool) {
+	while(pool) {
+		struct _stringpool *next = pool->next;
+		free(pool);
+		pool = next;
+	}
+}
+
+const char *
+_pbcS_build(struct _stringpool *pool, const char * str , int sz) {
+	size_t s = sz + 1;
+	if (s < PAGE_SIZE - pool->len) {
+		char * ret = pool->buffer + pool->len;
+		memcpy(pool->buffer + pool->len, str, s);
+		pool->len += s;
+		return ret;
+	}
+	if (s > PAGE_SIZE) {
+		struct _stringpool * next = (struct _stringpool *)malloc(sizeof(struct _stringpool) + s);
+		next->buffer = (char *)(next + 1);
+		memcpy(next->buffer, str, s);
+		next->len = s;
+		next->next = pool->next;
+		pool->next = next;
+		return next->buffer;
+	}
+	struct _stringpool *next = (struct _stringpool *)malloc(sizeof(struct _stringpool) + PAGE_SIZE);
+	next->buffer = pool->buffer;
+	next->next = pool->next;
+	next->len = pool->len;
+
+	pool->next = next;
+	pool->buffer = (char *)(next + 1);
+	memcpy(pool->buffer, str, s);
+	pool->len = s;
+	return pool->buffer;
+}