class Unicorn::TeeInput - unicorn-5.3.0 Documentation

# class Unicorn::TeeInput

Acts like tee(1) on an input input to provide a input-like stream while providing rewindable semantics through a File/StringIO backing store. On the first pass, the input is only read on demand so your Rack application can use input notification (upload progress and like). This should fully conform to the Rack::Lint::InputWrapper specification on the public API. This class is intended to be a strict interpretation of Rack::Lint::InputWrapper functionality and will not support any deviations from it.

When processing uploads, unicorn exposes a TeeInput object under “rack.input” of the Rack environment by default.

### Public Instance Methods

gets → string or nil click to toggle source

Reads the next “line'' from the I/O stream; lines are separated by the global record separator ($/, typically “n”). A global record separator of nil reads the entire unread contents of ios. Returns nil if called at the end of file. This takes zero arguments for strict Rack::Lint compatibility, unlike IO#gets.

Calls superclass method Unicorn::StreamInput#gets

    # File lib/unicorn/tee_input.rb, line 102
    def gets
      @socket ? tee(super) : @tmp.gets
    end

read([length [, buffer ]]) → string, buffer, or nil click to toggle source

Reads at most length bytes from the I/O stream, or to the end of file if length is omitted or is nil. length must be a non-negative integer or nil. If the optional buffer argument is present, it must reference a String, which will receive the data.

At end of file, it returns nil or “” depend on length. ios.read() and ios.read(nil) returns “”. ios.read(length [, buffer]) returns nil.

If the Content-Length of the HTTP request is known (as is the common case for POST requests), then ios.read(length [, buffer]) will block until the specified length is read (or it is the last chunk). Otherwise, for uncommon “Transfer-Encoding: chunked” requests, ios.read(length [, buffer]) will return immediately if there is any data and only block when nothing is available (providing IO#readpartial semantics).

Calls superclass method Unicorn::StreamInput#read

    # File lib/unicorn/tee_input.rb, line 89
    def read(*args)
      @socket ? tee(super) : @tmp.read(*args)
    end

rewind → 0 click to toggle source

Positions the ios pointer to the beginning of input, returns the offset (zero) of the `ios` pointer. Subsequent reads will start from the beginning of the previously-buffered input.

    # File lib/unicorn/tee_input.rb, line 112
    def rewind
      return 0 if 0 == @tmp.size
      consume! if @socket
      @tmp.rewind # Rack does not specify what the return value is here
    end

size → Integer click to toggle source

Returns the size of the input. For requests with a Content-Length header value, this will not read data off the socket and just return the value of the Content-Length header as an Integer.

For Transfer-Encoding:chunked requests, this requires consuming all of the input stream before returning since there's no other way to determine the size of the request body beforehand.

This method is no longer part of the Rack specification as of Rack 1.2, so its use is not recommended. This method only exists for compatibility with Rack applications designed for Rack 1.1 and earlier. Most applications should only need to call `read` with a specified `length` in a loop until it returns `nil`.

    # File lib/unicorn/tee_input.rb, line 62
    def size
      @len and return @len
      pos = @tmp.pos
      consume!
      @tmp.pos = pos
      @len = @tmp.size
    end

### Private Instance Methods

consume!() click to toggle source

consumes the stream of the socket

    # File lib/unicorn/tee_input.rb, line 121
    def consume!
      junk = ""
      nil while read(@@io_chunk_size, junk)
    end

tee(buffer) click to toggle source

    # File lib/unicorn/tee_input.rb, line 126
    def tee(buffer)
      @tmp.write(buffer) if buffer
      buffer
    end