node/src/node_buffer.h at 3768aaaea406dd32db2f74395f6414bcd26dba74 · kaichen/node · GitHub

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#ifndef NODE_BUFFER_H_

#define NODE_BUFFER_H_

#include <node.h>

#include <node_object_wrap.h>

#include <v8.h>

namespace node {

/* 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 Blob_;

class Buffer : public ObjectWrap {

public:

~Buffer();

static void Initialize(v8::Handle<v8::Object> target);

static Buffer* New(size_t length); // public constructor

static inline bool HasInstance(v8::Handle<v8::Value> val) {

if (!val->IsObject()) return false;

v8::Local<v8::Object> obj = val->ToObject();

return constructor_template->HasInstance(obj);

}

char* data();

size_t length() const { return length_; }

struct Blob_* blob() const { return blob_; }

int AsciiWrite(char *string, int offset, int length);

int Utf8Write(char *string, int offset, int length);

private:

static v8::Persistent<v8::FunctionTemplate> constructor_template;

static v8::Handle<v8::Value> New(const v8::Arguments &args);

static v8::Handle<v8::Value> Slice(const v8::Arguments &args);

static v8::Handle<v8::Value> BinarySlice(const v8::Arguments &args);

static v8::Handle<v8::Value> AsciiSlice(const v8::Arguments &args);

static v8::Handle<v8::Value> Utf8Slice(const v8::Arguments &args);

static v8::Handle<v8::Value> BinaryWrite(const v8::Arguments &args);

static v8::Handle<v8::Value> AsciiWrite(const v8::Arguments &args);

static v8::Handle<v8::Value> Utf8Write(const v8::Arguments &args);

static v8::Handle<v8::Value> ByteLength(const v8::Arguments &args);

static v8::Handle<v8::Value> Unpack(const v8::Arguments &args);

static v8::Handle<v8::Value> Copy(const v8::Arguments &args);

Buffer(size_t length);

Buffer(Buffer *parent, size_t start, size_t end);

size_t off_; // offset inside blob_

size_t length_; // length inside blob_

struct Blob_ *blob_;

};

} // namespace node buffer

#endif // NODE_BUFFER_H_

node/src/node_buffer.h at 3768aaaea406dd32db2f74395f6414bcd26dba74 · kaichen/node · GitHub

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