More bindings, beginning tcp server code in js

src/node_buffer.h

@@ -5,8 +5,53 @@
 
 namespace node {
 
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+
+/* A buffer is a chunk of memory stored outside the V8 heap, mirrored by an
+ * object in javascript. The object is not totally opaque, one can access
+ * individual bytes with [] and slice it into substrings or sub-buffers
+ * without copying memory.
+ *
+ * // return an ascii encoded string - no memory iscopied
+ * buffer.asciiSlide(0, 3) 
+ *
+ * // returns another buffer - no memory is copied
+ * buffer.slice(0, 3)
+ *
+ * Interally, each javascript buffer object is backed by a "struct buffer"
+ * object.  These "struct buffer" objects are either a root buffer (in the
+ * case that buffer->root == NULL) or slice objects (in which case
+ * buffer->root != NULL).  A root buffer is only GCed once all its slices
+ * are GCed.
+ */
+
+struct buffer {
+  v8::Persistent<v8::Object> handle;  // both
+  bool weak;                          // both
+  struct buffer *root;                // both (NULL for root)
+  size_t offset;                      // both (0 for root)
+  size_t length;                      // both
+  unsigned int refs;                  // root only
+  char bytes[1];                      // root only
+};
+
 void InitBuffer(v8::Handle<v8::Object> target);
 
+struct buffer* BufferUnwrap(v8::Handle<v8::Value> val);
+bool IsBuffer(v8::Handle<v8::Value> val);
+
+static inline char * buffer_p(struct buffer *buffer, size_t off) {
+  struct buffer *root = buffer->root ? buffer->root : buffer;
+  if (buffer->offset + off >= root->length) return NULL;
+  return reinterpret_cast<char*>(&(root->bytes) + buffer->offset + off);
+}
+
+static inline size_t buffer_remaining(struct buffer *buffer, size_t off) {
+  struct buffer *root = buffer->root ? buffer->root : buffer;
+  char *end = reinterpret_cast<char*>(&(root->bytes) + root->length);
+  return end - buffer_p(buffer, off);
+}
+
 }
 
 #endif  // NODE_BUFFER