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      1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.  Use of this
      2 // source code is governed by a BSD-style license that can be found in the
      3 // LICENSE file.
      4 
      5 #ifndef NET_FTP_FTP_CTRL_RESPONSE_BUFFER_H_
      6 #define NET_FTP_FTP_CTRL_RESPONSE_BUFFER_H_
      7 
      8 #include <queue>
      9 #include <string>
     10 #include <vector>
     11 
     12 #include "base/basictypes.h"
     13 
     14 namespace net {
     15 
     16 struct FtpCtrlResponse {
     17   static const int kInvalidStatusCode;
     18 
     19   FtpCtrlResponse() : status_code(kInvalidStatusCode) {}
     20 
     21   int status_code;                 // Three-digit status code.
     22   std::vector<std::string> lines;  // Response lines, without CRLFs.
     23 };
     24 
     25 class FtpCtrlResponseBuffer {
     26  public:
     27   FtpCtrlResponseBuffer() : multiline_(false) {
     28   }
     29 
     30   // Called when data is received from the control socket. Returns error code.
     31   int ConsumeData(const char* data, int data_length);
     32 
     33   bool ResponseAvailable() const {
     34     return !responses_.empty();
     35   }
     36 
     37   // Returns the next response. It is an error to call this function
     38   // unless ResponseAvailable returns true.
     39   FtpCtrlResponse PopResponse() {
     40     FtpCtrlResponse result = responses_.front();
     41     responses_.pop();
     42     return result;
     43   }
     44 
     45  private:
     46   struct ParsedLine {
     47     ParsedLine()
     48         : has_status_code(false),
     49           is_multiline(false),
     50           is_complete(false),
     51           status_code(FtpCtrlResponse::kInvalidStatusCode) {
     52     }
     53 
     54     // Indicates that this line begins with a valid 3-digit status code.
     55     bool has_status_code;
     56 
     57     // Indicates that this line has the dash (-) after the code, which
     58     // means a multiline response.
     59     bool is_multiline;
     60 
     61     // Indicates that this line could be parsed as a complete and valid
     62     // response line, without taking into account preceding lines (which
     63     // may change its meaning into a continuation of the previous line).
     64     bool is_complete;
     65 
     66     // Part of response parsed as status code.
     67     int status_code;
     68 
     69     // Part of response parsed as status text.
     70     std::string status_text;
     71 
     72     // Text before parsing, without terminating CRLF.
     73     std::string raw_text;
     74   };
     75 
     76   static ParsedLine ParseLine(const std::string& line);
     77 
     78   void ExtractFullLinesFromBuffer();
     79 
     80   // We keep not-yet-parsed data in a string buffer.
     81   std::string buffer_;
     82 
     83   std::queue<ParsedLine> lines_;
     84 
     85   // True if we are in the middle of parsing a multi-line response.
     86   bool multiline_;
     87 
     88   // When parsing a multiline response, we don't know beforehand if a line
     89   // will have a continuation. So always store last line of multiline response
     90   // so we can append the continuation to it.
     91   std::string line_buf_;
     92 
     93   // Keep the response data while we add all lines to it.
     94   FtpCtrlResponse response_buf_;
     95 
     96   // As we read full responses (possibly multiline), we add them to the queue.
     97   std::queue<FtpCtrlResponse> responses_;
     98 
     99   DISALLOW_COPY_AND_ASSIGN(FtpCtrlResponseBuffer);
    100 };
    101 
    102 }  // namespace net
    103 
    104 #endif  // NET_FTP_FTP_CTRL_RESPONSE_BUFFER_H_
    105