// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// http://code.google.com/p/protobuf/
//
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// modification, are permitted provided that the following conditions are
// met:
//
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// 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.
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//
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// 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 <string>
#include <map>
#include <google/protobuf/stubs/common.h>
namespace google {
namespace protobuf {
namespace io {
class ZeroCopyOutputStream; // zero_copy_stream.h
// 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, '$');
// 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.
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);
~Printer();
// 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 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);
// TODO(kenton): Overloaded versions with more variables? Three seems
// to be enough.
// 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:
const char variable_delimiter_;
ZeroCopyOutputStream* const output_;
char* buffer_;
int buffer_size_;
string indent_;
bool at_start_of_line_;
bool failed_;
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Printer);
};
} // namespace io
} // namespace protobuf
} // namespace google
#endif // GOOGLE_PROTOBUF_IO_PRINTER_H__