url/url_canon_stdstring.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef URL_URL_CANON_STDSTRING_H_
   6 #define URL_URL_CANON_STDSTRING_H_
   7
   8 // This header file defines a canonicalizer output method class for STL
   9 // strings. Because the canonicalizer tries not to be dependent on the STL,
  10 // we have segregated it here.
  11
  12 #include <string>
  13
  14 #include "base/compiler_specific.h"
  15 #include "url/url_canon.h"
  16
  17 namespace url_canon {
  18
  19 // Write into a std::string given in the constructor. This object does not own
  20 // the string itself, and the user must ensure that the string stays alive
  21 // throughout the lifetime of this object.
  22 //
  23 // The given string will be appended to; any existing data in the string will
  24 // be preserved. The caller should reserve() the amount of data in the string
  25 // they expect to be written. We will resize if necessary, but that's slow.
  26 //
  27 // Note that when canonicalization is complete, the string will likely have
  28 // unused space at the end because we make the string very big to start out
  29 // with (by |initial_size|). This ends up being important because resize
  30 // operations are slow, and because the base class needs to write directly
  31 // into the buffer.
  32 //
  33 // Therefore, the user should call Complete() before using the string that
  34 // this class wrote into.
  35 class StdStringCanonOutput : public CanonOutput {
  36  public:
  37   StdStringCanonOutput(std::string* str)
  38       : CanonOutput(),
  39         str_(str) {
  40     cur_len_ = static_cast<int>(str_->size());  // Append to existing data.
  41     str_->resize(str_->capacity());
  42     buffer_ = str_->empty() ? NULL : &(*str_)[0];
  43     buffer_len_ = static_cast<int>(str_->size());
  44   }
  45   virtual ~StdStringCanonOutput() {
  46     // Nothing to do, we don't own the string.
  47   }
  48
  49   // Must be called after writing has completed but before the string is used.
  50   void Complete() {
  51     str_->resize(cur_len_);
  52     buffer_len_ = cur_len_;
  53   }
  54
  55   virtual void Resize(int sz) OVERRIDE {
  56     str_->resize(sz);
  57     buffer_ = str_->empty() ? NULL : &(*str_)[0];
  58     buffer_len_ = sz;
  59   }
  60
  61  protected:
  62   std::string* str_;
  63 };
  64
  65 // An extension of the Replacements class that allows the setters to use
  66 // standard strings.
  67 //
  68 // The strings passed as arguments are not copied and must remain valid until
  69 // this class goes out of scope.
  70 template<typename STR>
  71 class StdStringReplacements :
  72     public url_canon::Replacements<typename STR::value_type> {
  73  public:
  74   void SetSchemeStr(const STR& s) {
  75     this->SetScheme(s.data(),
  76                     url_parse::Component(0, static_cast<int>(s.length())));
  77   }
  78   void SetUsernameStr(const STR& s) {
  79     this->SetUsername(s.data(),
  80                       url_parse::Component(0, static_cast<int>(s.length())));
  81   }
  82   void SetPasswordStr(const STR& s) {
  83     this->SetPassword(s.data(),
  84                       url_parse::Component(0, static_cast<int>(s.length())));
  85   }
  86   void SetHostStr(const STR& s) {
  87     this->SetHost(s.data(),
  88                   url_parse::Component(0, static_cast<int>(s.length())));
  89   }
  90   void SetPortStr(const STR& s) {
  91     this->SetPort(s.data(),
  92                   url_parse::Component(0, static_cast<int>(s.length())));
  93   }
  94   void SetPathStr(const STR& s) {
  95     this->SetPath(s.data(),
  96                   url_parse::Component(0, static_cast<int>(s.length())));
  97   }
  98   void SetQueryStr(const STR& s) {
  99     this->SetQuery(s.data(),
 100                    url_parse::Component(0, static_cast<int>(s.length())));
 101   }
 102   void SetRefStr(const STR& s) {
 103     this->SetRef(s.data(),
 104                  url_parse::Component(0, static_cast<int>(s.length())));
 105   }
 106 };
 107
 108 }  // namespace url_canon
 109
 110 #endif  // URL_URL_CANON_STDSTRING_H_