text: // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  // Author: kenton@google.com (Kenton Varda)
  //  Based on original Protocol Buffers design by
  //  Sanjay Ghemawat, Jeff Dean, and others.
  //
  // Utility class for writing text to a ZeroCopyOutputStream.
  
  #ifndef GOOGLE_PROTOBUF_IO_PRINTER_H__
  #define GOOGLE_PROTOBUF_IO_PRINTER_H__
  
  #include <map>
  #include <vector>
  #include <google/protobuf/stubs/common.h>
  
  namespace google {
  namespace protobuf {
  namespace io {
  
  class ZeroCopyOutputStream;     // zero_copy_stream.h
  
  // Records annotations about a Printer's output.
  class LIBPROTOBUF_EXPORT AnnotationCollector {
   public:
    // Records that the bytes in file_path beginning with begin_offset and ending
    // before end_offset are associated with the SourceCodeInfo-style path.
    virtual void AddAnnotation(size_t begin_offset, size_t end_offset,
                               const string& file_path,
                               const std::vector<int>& path) = 0;
  
    virtual ~AnnotationCollector() {}
  };
  
  // Records annotations about a Printer's output to the given protocol buffer,
  // assuming that the buffer has an ::Annotation message exposing path,
  // source_file, begin and end fields.
  template <typename AnnotationProto>
  class AnnotationProtoCollector : public AnnotationCollector {
   public:
    // annotation_proto is the protocol buffer to which new Annotations should be
    // added. It is not owned by the AnnotationProtoCollector.
    explicit AnnotationProtoCollector(AnnotationProto* annotation_proto)
        : annotation_proto_(annotation_proto) {}
  
    // Override for AnnotationCollector::AddAnnotation.
    virtual void AddAnnotation(size_t begin_offset, size_t end_offset,
                               const string& file_path,
                               const std::vector<int>& path) {
      typename AnnotationProto::Annotation* annotation =
          annotation_proto_->add_annotation();
      for (int i = 0; i < path.size(); ++i) {
        annotation->add_path(path[i]);
      }
      annotation->set_source_file(file_path);
      annotation->set_begin(begin_offset);
      annotation->set_end(end_offset);
    }
  
   private:
    // The protocol buffer to which new annotations should be added.
    AnnotationProto* const annotation_proto_;
  };
  
  // This simple utility class assists in code generation.  It basically
  // allows the caller to define a set of variables and then output some
  // text with variable substitutions.  Example usage:
  //
  //   Printer printer(output, '$');
  //   std::map<string, string> vars;
  //   vars["name"] = "Bob";
  //   printer.Print(vars, "My name is $name$.");
  //
  // The above writes "My name is Bob." to the output stream.
  //
  // Printer aggressively enforces correct usage, crashing (with assert failures)
  // in the case of undefined variables in debug builds. This helps greatly in
  // debugging code which uses it.
  //
  // If a Printer is constructed with an AnnotationCollector, it will provide it
  // with annotations that connect the Printer's output to paths that can identify
  // various descriptors.  In the above example, if person_ is a descriptor that
  // identifies Bob, we can associate the output string "My name is Bob." with
  // a source path pointing to that descriptor with:
  //
  //   printer.Annotate("name", person_);
  //
  // The AnnotationCollector will be sent an annotation linking the output range
  // covering "Bob" to the logical path provided by person_.  Tools may use
  // this association to (for example) link "Bob" in the output back to the
  // source file that defined the person_ descriptor identifying Bob.
  //
  // Annotate can only examine variables substituted during the last call to
  // Print.  It is invalid to refer to a variable that was used multiple times
  // in a single Print call.
  //
  // In full generality, one may specify a range of output text using a beginning
  // substitution variable and an ending variable.  The resulting annotation will
  // span from the first character of the substituted value for the beginning
  // variable to the last character of the substituted value for the ending
  // variable.  For example, the Annotate call above is equivalent to this one:
  //
  //   printer.Annotate("name", "name", person_);
  //
  // This is useful if multiple variables combine to form a single span of output
  // that should be annotated with the same source path.  For example:
  //
  //   Printer printer(output, '$');
  //   std::map<string, string> vars;
  //   vars["first"] = "Alice";
  //   vars["last"] = "Smith";
  //   printer.Print(vars, "My name is $first$ $last$.");
  //   printer.Annotate("first", "last", person_);
  //
  // This code would associate the span covering "Alice Smith" in the output with
  // the person_ descriptor.
  //
  // Note that the beginning variable must come before (or overlap with, in the
  // case of zero-sized substitution values) the ending variable.
  //
  // It is also sometimes useful to use variables with zero-sized values as
  // markers.  This avoids issues with multiple references to the same variable
  // and also allows annotation ranges to span literal text from the Print
  // templates:
  //
  //   Printer printer(output, '$');
  //   std::map<string, string> vars;
  //   vars["foo"] = "bar";
  //   vars["function"] = "call";
  //   vars["mark"] = "";
  //   printer.Print(vars, "$function$($foo$,$foo$)$mark$");
  //   printer.Annotate("function", "mark", call_);
  //
  // This code associates the span covering "call(bar,bar)" in the output with the
  // call_ descriptor.
  
  class LIBPROTOBUF_EXPORT Printer {
   public:
    // Create a printer that writes text to the given output stream.  Use the
    // given character as the delimiter for variables.
    Printer(ZeroCopyOutputStream* output, char variable_delimiter);
  
    // Create a printer that writes text to the given output stream.  Use the
    // given character as the delimiter for variables.  If annotation_collector
    // is not null, Printer will provide it with annotations about code written
    // to the stream.  annotation_collector is not owned by Printer.
    Printer(ZeroCopyOutputStream* output, char variable_delimiter,
            AnnotationCollector* annotation_collector);
  
    ~Printer();
  
    // Link a subsitution variable emitted by the last call to Print to the object
    // described by descriptor.
    template <typename SomeDescriptor>
    void Annotate(const char* varname, const SomeDescriptor* descriptor) {
      Annotate(varname, varname, descriptor);
    }
  
    // Link the output range defined by the substitution variables as emitted by
    // the last call to Print to the object described by descriptor. The range
    // begins at begin_varname's value and ends after the last character of the
    // value substituted for end_varname.
    template <typename SomeDescriptor>
    void Annotate(const char* begin_varname, const char* end_varname,
                  const SomeDescriptor* descriptor) {
      if (annotation_collector_ == NULL) {
        // Annotations aren't turned on for this Printer, so don't pay the cost
        // of building the location path.
        return;
      }
      std::vector<int> path;
      descriptor->GetLocationPath(&path);
      Annotate(begin_varname, end_varname, descriptor->file()->name(), path);
    }
  
    // Link a subsitution variable emitted by the last call to Print to the file
    // with path file_name.
    void Annotate(const char* varname, const string& file_name) {
      Annotate(varname, varname, file_name);
    }
  
    // Link the output range defined by the substitution variables as emitted by
    // the last call to Print to the file with path file_name. The range begins
    // at begin_varname's value and ends after the last character of the value
    // substituted for end_varname.
    void Annotate(const char* begin_varname, const char* end_varname,
                  const string& file_name) {
      if (annotation_collector_ == NULL) {
        // Annotations aren't turned on for this Printer.
        return;
      }
      std::vector<int> empty_path;
      Annotate(begin_varname, end_varname, file_name, empty_path);
    }
  
    // Print some text after applying variable substitutions.  If a particular
    // variable in the text is not defined, this will crash.  Variables to be
    // substituted are identified by their names surrounded by delimiter
    // characters (as given to the constructor).  The variable bindings are
    // defined by the given map.
    void Print(const std::map<string, string>& variables, const char* text);
  
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable, const string& value);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable1, const string& value1,
                                 const char* variable2, const string& value2);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable1, const string& value1,
                                 const char* variable2, const string& value2,
                                 const char* variable3, const string& value3);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable1, const string& value1,
                                 const char* variable2, const string& value2,
                                 const char* variable3, const string& value3,
                                 const char* variable4, const string& value4);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable1, const string& value1,
                                 const char* variable2, const string& value2,
                                 const char* variable3, const string& value3,
                                 const char* variable4, const string& value4,
                                 const char* variable5, const string& value5);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable1, const string& value1,
                                 const char* variable2, const string& value2,
                                 const char* variable3, const string& value3,
                                 const char* variable4, const string& value4,
                                 const char* variable5, const string& value5,
                                 const char* variable6, const string& value6);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable1, const string& value1,
                                 const char* variable2, const string& value2,
                                 const char* variable3, const string& value3,
                                 const char* variable4, const string& value4,
                                 const char* variable5, const string& value5,
                                 const char* variable6, const string& value6,
                                 const char* variable7, const string& value7);
    // Like the first Print(), except the substitutions are given as parameters.
    void Print(const char* text, const char* variable1, const string& value1,
                                 const char* variable2, const string& value2,
                                 const char* variable3, const string& value3,
                                 const char* variable4, const string& value4,
                                 const char* variable5, const string& value5,
                                 const char* variable6, const string& value6,
                                 const char* variable7, const string& value7,
                                 const char* variable8, const string& value8);
  
    // Indent text by two spaces.  After calling Indent(), two spaces will be
    // inserted at the beginning of each line of text.  Indent() may be called
    // multiple times to produce deeper indents.
    void Indent();
  
    // Reduces the current indent level by two spaces, or crashes if the indent
    // level is zero.
    void Outdent();
  
    // Write a string to the output buffer.
    // This method does not look for newlines to add indentation.
    void PrintRaw(const string& data);
  
    // Write a zero-delimited string to output buffer.
    // This method does not look for newlines to add indentation.
    void PrintRaw(const char* data);
  
    // Write some bytes to the output buffer.
    // This method does not look for newlines to add indentation.
    void WriteRaw(const char* data, int size);
  
    // True if any write to the underlying stream failed.  (We don't just
    // crash in this case because this is an I/O failure, not a programming
    // error.)
    bool failed() const { return failed_; }
  
   private:
    // Link the output range defined by the substitution variables as emitted by
    // the last call to Print to the object found at the SourceCodeInfo-style path
    // in a file with path file_path. The range begins at the start of
    // begin_varname's value and ends after the last character of the value
    // substituted for end_varname. Note that begin_varname and end_varname
    // may refer to the same variable.
    void Annotate(const char* begin_varname, const char* end_varname,
                  const string& file_path, const std::vector<int>& path);
  
    // Copy size worth of bytes from data to buffer_.
    void CopyToBuffer(const char* data, int size);
  
    const char variable_delimiter_;
  
    ZeroCopyOutputStream* const output_;
    char* buffer_;
    int buffer_size_;
    // The current position, in bytes, in the output stream.  This is equivalent
    // to the total number of bytes that have been written so far.  This value is
    // used to calculate annotation ranges in the substitutions_ map below.
    size_t offset_;
  
    string indent_;
    bool at_start_of_line_;
    bool failed_;
  
    // A map from variable name to [start, end) offsets in the output buffer.
    // These refer to the offsets used for a variable after the last call to
    // Print.  If a variable was used more than once, the entry used in
    // this map is set to a negative-length span.  For singly-used variables, the
    // start offset is the beginning of the substitution; the end offset is the
    // last byte of the substitution plus one (such that (end - start) is the
    // length of the substituted string).
    std::map<string, std::pair<size_t, size_t> > substitutions_;
  
    // Keeps track of the keys in substitutions_ that need to be updated when
    // indents are inserted. These are keys that refer to the beginning of the
    // current line.
    std::vector<string> line_start_variables_;
  
    // Returns true and sets range to the substitution range in the output for
    // varname if varname was used once in the last call to Print. If varname
    // was not used, or if it was used multiple times, returns false (and
    // fails a debug assertion).
    bool GetSubstitutionRange(const char* varname,
                              std::pair<size_t, size_t>* range);
  
    // If non-null, annotation_collector_ is used to store annotations about
    // generated code.
    AnnotationCollector* const annotation_collector_;
  
    GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Printer);
  };
  
  }  // namespace io
  }  // namespace protobuf
  
  }  // namespace google
  #endif  // GOOGLE_PROTOBUF_IO_PRINTER_H__
  