Refactor GetLines to share common code, fix whitespace removal at end of line.

1 files changed, 176 insertions, 0 deletions

diff --git a/lib/common/GetLine.cpp b/lib/common/GetLine.cpp
new file mode 100644
index 00000000..e6b26c8a
--- /dev/null
+++ b/lib/common/GetLine.cpp
@@ -0,0 +1,176 @@
+// --------------------------------------------------------------------------
+//
+// File
+//		Name:    GetLine.cpp
+//		Purpose: Common base class for line based file descriptor reading
+//		Created: 2011/04/22
+//
+// --------------------------------------------------------------------------
+
+#include "Box.h"
+
+#include <sys/types.h>
+
+#ifdef HAVE_UNISTD_H
+	#include <unistd.h>
+#endif
+
+#include "GetLine.h"
+#include "CommonException.h"
+
+#include "MemLeakFindOn.h"
+
+// utility whitespace function
+inline bool iw(int c)
+{
+	return (c == ' ' || c == '\t' || c == '\v' || c == '\f'); // \r, \n are already excluded
+}
+
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    GetLine::GetLine(int)
+//		Purpose: Constructor, taking file descriptor
+//		Created: 2011/04/22
+//
+// --------------------------------------------------------------------------
+GetLine::GetLine()
+: mLineNumber(0),
+  mBufferBegin(0),
+  mBytesInBuffer(0),
+  mPendingEOF(false),
+  mEOF(false)
+{ }
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    GetLine::GetLineInternal(std::string &, bool, int)
+//		Purpose: Gets a line from the file, returning it in rOutput.
+//			 If Preprocess is true, leading and trailing
+//			 whitespace is removed, and comments (after #)  are
+//			 deleted. Returns true if a line is available now,
+//			 false if retrying may get a line (eg timeout,
+//			 signal), and exceptions if it's EOF.
+//		Created: 2011/04/22
+//
+// --------------------------------------------------------------------------
+bool GetLine::GetLineInternal(std::string &rOutput, bool Preprocess,
+	int Timeout)
+{
+	// EOF?
+	if(mEOF) {THROW_EXCEPTION(CommonException, GetLineEOF)}
+	
+	// Initialise string to stored into
+	rOutput = mPendingString;
+	mPendingString.erase();
+
+	bool foundLineEnd = false;
+
+	while(!foundLineEnd && !mEOF)
+	{
+		// Use any bytes left in the buffer
+		while(mBufferBegin < mBytesInBuffer)
+		{
+			int c = mBuffer[mBufferBegin++];
+			if(c == '\r')
+			{
+				// Ignore nasty Windows line ending extra chars
+			}
+			else if(c == '\n')
+			{
+				// Line end!
+				foundLineEnd = true;
+				break;
+			}
+			else
+			{
+				// Add to string
+				rOutput += c;
+			}
+			
+			// Implicit line ending at EOF
+			if(mBufferBegin >= mBytesInBuffer && mPendingEOF)
+			{
+				foundLineEnd = true;
+			}
+		}
+		
+		// Check size
+		if(rOutput.size() > GETLINE_MAX_LINE_SIZE)
+		{
+			THROW_EXCEPTION(CommonException, GetLineTooLarge)
+		}
+		
+		// Read more in?
+		if(!foundLineEnd && mBufferBegin >= mBytesInBuffer && !mPendingEOF)
+		{
+			int bytes = ReadMore(Timeout);
+			
+			// Error?
+			if(bytes == -1)
+			{
+				THROW_EXCEPTION(CommonException, OSFileError)
+			}
+			
+			// Adjust buffer info
+			mBytesInBuffer = bytes;
+			mBufferBegin = 0;
+			
+			// No data returned?
+			if(bytes == 0 && IsStreamDataLeft())
+			{
+			       // store string away
+			       mPendingString = rOutput;
+			       // Return false;
+			       return false;
+			}
+		}
+		
+		// EOF?
+		if(mPendingEOF && mBufferBegin >= mBytesInBuffer)
+		{
+			// File is EOF, and now we've depleted the buffer completely, so tell caller as well.
+			mEOF = true;
+		}
+	}
+
+	if(Preprocess)
+	{
+		// Check for comment char, but char before must be whitespace
+		// end points to a gap between characters, may equal start if
+		// the string to be extracted has zero length, and indexes the
+		// first character not in the string (== length, or a # mark
+		// or whitespace)
+		int end = 0;
+		int size = rOutput.size();
+		while(end < size)
+		{
+			if(rOutput[end] == '#' && (end == 0 || (iw(rOutput[end-1]))))
+			{
+				break;
+			}
+			end++;
+		}
+		
+		// Remove whitespace
+		int begin = 0;
+		while(begin < size && iw(rOutput[begin]))
+		{
+			begin++;
+		}
+
+		while(end > begin && end <= size && iw(rOutput[end-1]))
+		{
+			end--;
+		}
+		
+		// Return a sub string
+		rOutput = rOutput.substr(begin, end - begin);
+	}
+
+	return true;
+}
+
+