DnsClient refactoring + features (timeout, suffix search, server rotation).

net/dns/dns_response.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_DNS_DNS_RESPONSE_H_
 #define NET_DNS_DNS_RESPONSE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 28 matching lines @@
 class NET_EXPORT_PRIVATE DnsRecordParser {
  public:
   // Construct an uninitialized iterator.
   DnsRecordParser();
 
   // Construct an iterator to process the |packet| of given |length|.
   // |offset| points to the beginning of the answer section.
   DnsRecordParser(const void* packet, size_t length, size_t offset);
 
   // Returns |true| if initialized.
-  bool IsValid() const { return packet_ != NULL; }
+  bool is_valid() const { return packet_ != NULL; }

[cbentzel, 2012/01/13 22:17:25]

Old naming scheme is more appropriate here. 

 
   // Returns |true| if no more bytes remain in the packet.
   bool AtEnd() const { return cur_ == packet_ + length_; }
 
+  // Returns current offset into the packet.
+  size_t offset() const { return cur_ - packet_; }
+
   // Parses a (possibly compressed) DNS name from the packet starting at
   // |pos|. Stores output (even partial) in |out| unless |out| is NULL. |out|
   // is stored in the dotted form, e.g., "example.com". Returns number of bytes
   // consumed or 0 on failure.
   // This is exposed to allow parsing compressed names within RRDATA for TYPEs
   // such as NS, CNAME, PTR, MX, SOA.
   // See RFC 1035 section 4.1.4.
   int ParseName(const void* pos, std::string* out) const;
 
   // Parses the next resource record. Returns true if succeeded.
@@ skipping 20 matching lines @@
   ~DnsResponse();
 
   // Internal buffer accessor into which actual bytes of response will be
   // read.
   IOBufferWithSize* io_buffer() { return io_buffer_.get(); }
 
   // Returns false if the packet is shorter than the header or does not match
   // |query| id or question.
   bool InitParse(int nbytes, const DnsQuery& query);
 
+  // Returns true if response is valid, that is, after successful InitParse.
+  bool is_valid() const;

[cbentzel, 2012/01/13 22:17:25]

Ditto, prefer IsValid().

+
+  // All of the methods below are valid only if the response is valid.
+
   // Accessors for the header.
-  uint8 flags0() const;  // first byte of flags
-  uint8 flags1() const;  // second byte of flags excluding rcode
+  uint16 flags() const;  // excluding rcode
   uint8 rcode() const;
   int answer_count() const;
 
-  // Returns an iterator to the resource records in the answer section. Must be
-  // called after InitParse. The iterator is valid only in the scope of the
-  // DnsResponse.
+  // Accessors to the question. The qname is unparsed.
+  base::StringPiece qname() const;

[cbentzel, 2012/01/13 22:17:25]

Where are these being used? 

[szym, 2012/01/17 15:38:25]

I'm not sure these will be used outside of tests. DnsTransaction::GetType()
should match DnsResponse::qtype() and qname() will be accessed via
GetDottedName().

+  uint16 qtype() const;
+
+  // Returns qname in dotted format.
+  std::string GetDottedName() const;
+
+  // Returns an iterator to the resource records in the answer section.
+  // The iterator is valid only in the scope of the DnsResponse.
+  // This operation is idempotent.
   DnsRecordParser Parser() const;
 
  private:
   // Convenience for header access.
   const dns_protocol::Header* header() const;
 
   // Buffer into which response bytes are read.
   scoped_refptr<IOBufferWithSize> io_buffer_;
 
   // Iterator constructed after InitParse positioned at the answer section.
+  // It is never updated afterwards, so can be used in accessors.
   DnsRecordParser parser_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsResponse);
 };
 
 }  // namespace net
 
 #endif  // NET_DNS_DNS_RESPONSE_H_