Implemented FileWriteStream with buffering

git-svn-id: https://rapidjson.googlecode.com/svn/trunk@23 c5894555-1306-4e8d-425f-1f6f381ee07c

example/condense/condense.cpp

@@ -5,18 +5,21 @@
 
 #include "rapidjson/reader.h"
 #include "rapidjson/writer.h"
-#include "rapidjson/filestream.h"
+#include "rapidjson/filereadstream.h"
+#include "rapidjson/filewritestream.h"
 
 using namespace rapidjson;
 
 int main(int argc, char* argv[]) {
 	// Prepare JSON reader and input stream.
 	Reader reader;
-	FileStream is(stdin);
+	char readBuffer[65536];
+	FileReadStream is(stdin, readBuffer, sizeof(readBuffer));
 
 	// Prepare JSON writer and output stream.
-	FileStream os(stdout);
+	char writeBuffer[65536];
-	Writer<FileStream> writer(os);
+	FileWriteStream os(stdout, writeBuffer, sizeof(writeBuffer));
+	Writer<FileWriteStream> writer(os);
 
 	// JSON reader parse from the input stream and let writer generate the output.
 	if (!reader.Parse<0>(is, writer)) {

example/pretty/pretty.cpp

@@ -2,18 +2,21 @@
 
 #include "rapidjson/reader.h"
 #include "rapidjson/prettywriter.h"
-#include "rapidjson/filestream.h"
+#include "rapidjson/filereadstream.h"
+#include "rapidjson/filewritestream.h"
 
 using namespace rapidjson;
 
 int main(int argc, char* argv[]) {
 	// Prepare reader and input stream.
 	Reader reader;
-	FileStream is(stdin);
+	char readBuffer[65536];
+	FileReadStream is(stdin, readBuffer, sizeof(readBuffer));
 
 	// Prepare writer and output stream.
-	FileStream os(stdout);
+	char writeBuffer[65536];
-	PrettyWriter<FileStream> writer(os);
+	FileWriteStream os(stdout, writeBuffer, sizeof(writeBuffer));
+	PrettyWriter<FileWriteStream> writer(os);
 
 	// JSON reader parse from the input stream and let writer generate the output.
 	if (!reader.Parse<0>(is, writer)) {

include/rapidjson/filereadstream.h

@@ -46,7 +46,6 @@ private:
 			if (readCount_ < bufferSize_) {
 				buffer_[readCount_] = '\0';
 				++bufferLast_;
-				++count_;
 				eof_ = true;
 			}
 		}

include/rapidjson/filestream.h

@@ -34,10 +34,8 @@ private:
 			current_ = (char)c;
 			count_++;
 		}
-		else if (current_ != '\0') {
+		else if (current_ != '\0')
 			current_ = '\0';
-			count_++;
-		}
 	}
 
 	FILE* fp_;

include/rapidjson/filewritestream.h

@@ -0,0 +1,73 @@
+#ifndef RAPIDJSON_FILEWRITESTREAM_H_
+#define RAPIDJSON_FILEWRITESTREAM_H_
+
+#include "rapidjson.h"
+#include <cstdio>
+
+namespace rapidjson {
+
+//! Wrapper of C file stream for input using fread().
+/*!
+	\implements Stream
+*/
+class FileWriteStream {
+public:
+	typedef char Ch;	//!< Character type. Only support char.
+
+	FileWriteStream(FILE* fp, char* buffer, size_t bufferSize) : fp_(fp), buffer_(buffer), bufferEnd_(buffer + bufferSize), current_(buffer_) { 
+		RAPIDJSON_ASSERT(fp_ != 0);
+	}
+
+	void Put(char c) { 
+		if (current_ >= bufferEnd_)
+			Flush();
+
+		*current_++ = c;
+	}
+
+	void PutN(char c, size_t n) {
+		size_t avail = bufferEnd_ - current_;
+		while (n > avail) {
+			memset(current_, c, avail);
+			current_ += avail;
+			Flush();
+			n -= avail;
+			avail = bufferEnd_ - current_;
+		}
+
+		if (n > 0) {
+			memset(current_, c, n);
+			current_ += n;
+		}
+	}
+
+	void Flush() {
+		if (current_ != buffer_) {
+			fwrite(buffer_, 1, current_ - buffer_, fp_);
+			current_ = buffer_;
+		}
+	}
+
+	// Not implemented
+	char Peek() const { RAPIDJSON_ASSERT(false); }
+	char Take() { RAPIDJSON_ASSERT(false); }
+	size_t Tell() const { RAPIDJSON_ASSERT(false); }
+	char* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
+	size_t PutEnd(char*) { RAPIDJSON_ASSERT(false); return 0; }
+
+private:
+	FILE* fp_;
+	char *buffer_;
+	char *bufferEnd_;
+	char *current_;
+};
+
+//! Implement specialized version of PutN() with memset() for better performance.
+template<>
+inline void PutN(FileWriteStream& stream, char c, size_t n) {
+	stream.PutN(c, n);
+}
+
+} // namespace rapidjson
+
+#endif // RAPIDJSON_FILESTREAM_H_

test/unittest/filestreamtest.cpp

@@ -1,6 +1,7 @@
 #include "unittest.h"
 #include "rapidjson/filestream.h"
 #include "rapidjson/filereadstream.h"
+#include "rapidjson/filewritestream.h"
 
 using namespace rapidjson;
 
@@ -17,7 +18,6 @@ class FileStreamTest : public ::testing::Test {
 		json_ = (char*)malloc(length_ + 1);
 		fread(json_, 1, length_, fp);
 		json_[length_] = '\0';
-		length_++;	// include the null terminator
 		fclose(fp);
 	}
 
@@ -31,7 +31,7 @@ protected:
 	size_t length_;
 };
 
-TEST_F(FileStreamTest, Read) {
+TEST_F(FileStreamTest, FileStream_Read) {
 	FILE *fp = fopen(filename_, "rb");
 	ASSERT_TRUE(fp != 0);
 	FileStream s(fp);
@@ -48,18 +48,16 @@ TEST_F(FileStreamTest, Read) {
 	fclose(fp);
 }
 
-TEST_F(FileStreamTest, BufferedRead) {
+TEST_F(FileStreamTest, FileReadStream) {
 	FILE *fp = fopen(filename_, "rb");
 	ASSERT_TRUE(fp != 0);
 	char buffer[65536];
 	FileReadStream s(fp, buffer, sizeof(buffer));
 
 	for (size_t i = 0; i < length_; i++) {
-		if (json_[i] != s.Peek())
+		EXPECT_EQ(json_[i], s.Peek());
-			__asm int 3;
+		EXPECT_EQ(json_[i], s.Peek());	// 2nd time should be the same
-		ASSERT_EQ(json_[i], s.Peek());
+		EXPECT_EQ(json_[i], s.Take());
-		ASSERT_EQ(json_[i], s.Peek());	// 2nd time should be the same
-		ASSERT_EQ(json_[i], s.Take());
 	}
 
 	EXPECT_EQ(length_, s.Tell());
@@ -67,3 +65,29 @@ TEST_F(FileStreamTest, BufferedRead) {
 
 	fclose(fp);
 }
+
+TEST_F(FileStreamTest, FileWriteStream) {
+	char filename[L_tmpnam];
+	tmpnam(filename);
+
+	FILE *fp = fopen(filename, "wb");
+	char buffer[65536];
+	FileWriteStream os(fp, buffer, sizeof(buffer));
+	for (size_t i = 0; i < length_; i++)
+		os.Put(json_[i]);
+	os.Flush();
+	fclose(fp);
+
+	// Read it back to verify
+	fp = fopen(filename, "rb");
+	FileReadStream is(fp, buffer, sizeof(buffer));
+
+	for (size_t i = 0; i < length_; i++)
+		EXPECT_EQ(json_[i], is.Take());
+
+	EXPECT_EQ(length_, is.Tell());
+	fclose(fp);
+
+	//std::cout << filename << std::endl;
+	remove(filename);
+}