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// 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 <string>
#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 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 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, '$');
// 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, '$');
// 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, '$');
// map<string, string> vars;
// vars["foo"] = "bar";
// vars["function"] = "call";
// vars["mark"] = "";
// printer.Print(vars, "$function$($foo$,$foo$)$mark$");
// printer.Annotate("function", "rmark", 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;
}
vector<int> path;
descriptor->GetLocationPath(&path);
Annotate(begin_varname, end_varname, descriptor->file()->name(), 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 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 vector<int>& path);
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).
map<string, pair<size_t, size_t> > substitutions_;
// 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, 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__