node/src/string_bytes.h

// Copyright Joyent, Inc. and other Node contributors.
//
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// "Software"), to deal in the Software without restriction, including
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//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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#ifndef SRC_STRING_BYTES_H_
#define SRC_STRING_BYTES_H_

// Decodes a v8::Handle<v8::String> or Buffer to a raw char*

#include "v8.h"
#include "node.h"

namespace node {

class StringBytes {
 public:
  // Does the string match the encoding? Quick but non-exhaustive.
  // Example: a HEX string must have a length that's a multiple of two.
  // FIXME(bnoordhuis) IsMaybeValidString()? Naming things is hard...
  static bool IsValidString(v8::Handle<v8::String> string, enum encoding enc);

  // Fast, but can be 2 bytes oversized for Base64, and
  // as much as triple UTF-8 strings <= 65536 chars in length
  static size_t StorageSize(v8::Handle<v8::Value> val, enum encoding enc);

  // Precise byte count, but slightly slower for Base64 and
  // very much slower for UTF-8
  static size_t Size(v8::Handle<v8::Value> val, enum encoding enc);

  // If the string is external then assign external properties to data and len,
  // then return true. If not return false.
  static bool GetExternalParts(v8::Handle<v8::Value> val,
                               const char** data,
                               size_t* len);

  // Write the bytes from the string or buffer into the char*
  // returns the number of bytes written, which will always be
  // <= buflen.  Use StorageSize/Size first to know how much
  // memory to allocate.
  static size_t Write(char* buf,
                      size_t buflen,
                      v8::Handle<v8::Value> val,
                      enum encoding enc,
                      int* chars_written = NULL);

  // Take the bytes in the src, and turn it into a Buffer or String.
  static v8::Local<v8::Value> Encode(const char* buf,
                                     size_t buflen,
                                     enum encoding encoding);
};

}  // namespace node

#endif  // SRC_STRING_BYTES_H_