Initial commit

1 files changed, 296 insertions, 0 deletions

diff --git a/node_modules/fd-slicer/index.js b/node_modules/fd-slicer/index.js
new file mode 100644
index 0000000..65d32a3
--- /dev/null
+++ b/node_modules/fd-slicer/index.js
@@ -0,0 +1,296 @@
+var fs = require('fs');
+var util = require('util');
+var stream = require('stream');
+var Readable = stream.Readable;
+var Writable = stream.Writable;
+var PassThrough = stream.PassThrough;
+var Pend = require('pend');
+var EventEmitter = require('events').EventEmitter;
+
+exports.createFromBuffer = createFromBuffer;
+exports.createFromFd = createFromFd;
+exports.BufferSlicer = BufferSlicer;
+exports.FdSlicer = FdSlicer;
+
+util.inherits(FdSlicer, EventEmitter);
+function FdSlicer(fd, options) {
+  options = options || {};
+  EventEmitter.call(this);
+
+  this.fd = fd;
+  this.pend = new Pend();
+  this.pend.max = 1;
+  this.refCount = 0;
+  this.autoClose = !!options.autoClose;
+}
+
+FdSlicer.prototype.read = function(buffer, offset, length, position, callback) {
+  var self = this;
+  self.pend.go(function(cb) {
+    fs.read(self.fd, buffer, offset, length, position, function(err, bytesRead, buffer) {
+      cb();
+      callback(err, bytesRead, buffer);
+    });
+  });
+};
+
+FdSlicer.prototype.write = function(buffer, offset, length, position, callback) {
+  var self = this;
+  self.pend.go(function(cb) {
+    fs.write(self.fd, buffer, offset, length, position, function(err, written, buffer) {
+      cb();
+      callback(err, written, buffer);
+    });
+  });
+};
+
+FdSlicer.prototype.createReadStream = function(options) {
+  return new ReadStream(this, options);
+};
+
+FdSlicer.prototype.createWriteStream = function(options) {
+  return new WriteStream(this, options);
+};
+
+FdSlicer.prototype.ref = function() {
+  this.refCount += 1;
+};
+
+FdSlicer.prototype.unref = function() {
+  var self = this;
+  self.refCount -= 1;
+
+  if (self.refCount > 0) return;
+  if (self.refCount < 0) throw new Error("invalid unref");
+
+  if (self.autoClose) {
+    fs.close(self.fd, onCloseDone);
+  }
+
+  function onCloseDone(err) {
+    if (err) {
+      self.emit('error', err);
+    } else {
+      self.emit('close');
+    }
+  }
+};
+
+util.inherits(ReadStream, Readable);
+function ReadStream(context, options) {
+  options = options || {};
+  Readable.call(this, options);
+
+  this.context = context;
+  this.context.ref();
+
+  this.start = options.start || 0;
+  this.endOffset = options.end;
+  this.pos = this.start;
+  this.destroyed = false;
+}
+
+ReadStream.prototype._read = function(n) {
+  var self = this;
+  if (self.destroyed) return;
+
+  var toRead = Math.min(self._readableState.highWaterMark, n);
+  if (self.endOffset != null) {
+    toRead = Math.min(toRead, self.endOffset - self.pos);
+  }
+  if (toRead <= 0) {
+    self.destroyed = true;
+    self.push(null);
+    self.context.unref();
+    return;
+  }
+  self.context.pend.go(function(cb) {
+    if (self.destroyed) return cb();
+    var buffer = new Buffer(toRead);
+    fs.read(self.context.fd, buffer, 0, toRead, self.pos, function(err, bytesRead) {
+      if (err) {
+        self.destroy(err);
+      } else if (bytesRead === 0) {
+        self.destroyed = true;
+        self.push(null);
+        self.context.unref();
+      } else {
+        self.pos += bytesRead;
+        self.push(buffer.slice(0, bytesRead));
+      }
+      cb();
+    });
+  });
+};
+
+ReadStream.prototype.destroy = function(err) {
+  if (this.destroyed) return;
+  err = err || new Error("stream destroyed");
+  this.destroyed = true;
+  this.emit('error', err);
+  this.context.unref();
+};
+
+util.inherits(WriteStream, Writable);
+function WriteStream(context, options) {
+  options = options || {};
+  Writable.call(this, options);
+
+  this.context = context;
+  this.context.ref();
+
+  this.start = options.start || 0;
+  this.endOffset = (options.end == null) ? Infinity : +options.end;
+  this.bytesWritten = 0;
+  this.pos = this.start;
+  this.destroyed = false;
+
+  this.on('finish', this.destroy.bind(this));
+}
+
+WriteStream.prototype._write = function(buffer, encoding, callback) {
+  var self = this;
+  if (self.destroyed) return;
+
+  if (self.pos + buffer.length > self.endOffset) {
+    var err = new Error("maximum file length exceeded");
+    err.code = 'ETOOBIG';
+    self.destroy();
+    callback(err);
+    return;
+  }
+  self.context.pend.go(function(cb) {
+    if (self.destroyed) return cb();
+    fs.write(self.context.fd, buffer, 0, buffer.length, self.pos, function(err, bytes) {
+      if (err) {
+        self.destroy();
+        cb();
+        callback(err);
+      } else {
+        self.bytesWritten += bytes;
+        self.pos += bytes;
+        self.emit('progress');
+        cb();
+        callback();
+      }
+    });
+  });
+};
+
+WriteStream.prototype.destroy = function() {
+  if (this.destroyed) return;
+  this.destroyed = true;
+  this.context.unref();
+};
+
+util.inherits(BufferSlicer, EventEmitter);
+function BufferSlicer(buffer, options) {
+  EventEmitter.call(this);
+
+  options = options || {};
+  this.refCount = 0;
+  this.buffer = buffer;
+  this.maxChunkSize = options.maxChunkSize || Number.MAX_SAFE_INTEGER;
+}
+
+BufferSlicer.prototype.read = function(buffer, offset, length, position, callback) {
+  var end = position + length;
+  var delta = end - this.buffer.length;
+  var written = (delta > 0) ? delta : length;
+  this.buffer.copy(buffer, offset, position, end);
+  setImmediate(function() {
+    callback(null, written);
+  });
+};
+
+BufferSlicer.prototype.write = function(buffer, offset, length, position, callback) {
+  buffer.copy(this.buffer, position, offset, offset + length);
+  setImmediate(function() {
+    callback(null, length, buffer);
+  });
+};
+
+BufferSlicer.prototype.createReadStream = function(options) {
+  options = options || {};
+  var readStream = new PassThrough(options);
+  readStream.destroyed = false;
+  readStream.start = options.start || 0;
+  readStream.endOffset = options.end;
+  // by the time this function returns, we'll be done.
+  readStream.pos = readStream.endOffset || this.buffer.length;
+
+  // respect the maxChunkSize option to slice up the chunk into smaller pieces.
+  var entireSlice = this.buffer.slice(readStream.start, readStream.pos);
+  var offset = 0;
+  while (true) {
+    var nextOffset = offset + this.maxChunkSize;
+    if (nextOffset >= entireSlice.length) {
+      // last chunk
+      if (offset < entireSlice.length) {
+        readStream.write(entireSlice.slice(offset, entireSlice.length));
+      }
+      break;
+    }
+    readStream.write(entireSlice.slice(offset, nextOffset));
+    offset = nextOffset;
+  }
+
+  readStream.end();
+  readStream.destroy = function() {
+    readStream.destroyed = true;
+  };
+  return readStream;
+};
+
+BufferSlicer.prototype.createWriteStream = function(options) {
+  var bufferSlicer = this;
+  options = options || {};
+  var writeStream = new Writable(options);
+  writeStream.start = options.start || 0;
+  writeStream.endOffset = (options.end == null) ? this.buffer.length : +options.end;
+  writeStream.bytesWritten = 0;
+  writeStream.pos = writeStream.start;
+  writeStream.destroyed = false;
+  writeStream._write = function(buffer, encoding, callback) {
+    if (writeStream.destroyed) return;
+
+    var end = writeStream.pos + buffer.length;
+    if (end > writeStream.endOffset) {
+      var err = new Error("maximum file length exceeded");
+      err.code = 'ETOOBIG';
+      writeStream.destroyed = true;
+      callback(err);
+      return;
+    }
+    buffer.copy(bufferSlicer.buffer, writeStream.pos, 0, buffer.length);
+
+    writeStream.bytesWritten += buffer.length;
+    writeStream.pos = end;
+    writeStream.emit('progress');
+    callback();
+  };
+  writeStream.destroy = function() {
+    writeStream.destroyed = true;
+  };
+  return writeStream;
+};
+
+BufferSlicer.prototype.ref = function() {
+  this.refCount += 1;
+};
+
+BufferSlicer.prototype.unref = function() {
+  this.refCount -= 1;
+
+  if (this.refCount < 0) {
+    throw new Error("invalid unref");
+  }
+};
+
+function createFromBuffer(buffer, options) {
+  return new BufferSlicer(buffer, options);
+}
+
+function createFromFd(fd, options) {
+  return new FdSlicer(fd, options);
+}