Bu::Buffer actually works, and works really well. I dig it. Bu::BZip2 now

follows the new filter guidelines, where read and write report the amount of
data consumed, not the amount processed.  I.e. when writing, it reports how
much of your incoming data it used, not how many bytes it wrote on the other
end.

1 files changed, 118 insertions, 2 deletions

diff --git a/src/buffer.cpp b/src/buffer.cpp
index fef64b1..5e7fb9a 100644
--- a/src/buffer.cpp
+++ b/src/buffer.cpp
@@ -1,18 +1,31 @@
+/*
+ * Copyright (C) 2007-2008 Xagasoft, All rights reserved.
+ *
+ * This file is part of the libbu++ library and is released under the
+ * terms of the license contained in the file LICENSE.
+ */
+
 #include "bu/buffer.h"
 
-Bu::Buffer::Buffer( Bu::Stream &rNext, int iBufsize ) :
+Bu::Buffer::Buffer( Bu::Stream &rNext, int iBufSize ) :
         Bu::Filter( rNext ),
         sSoFar( 0 ),
         iBufSize( iBufSize ),
         sReadBuf( NULL ),
         sWriteBuf( NULL ),
         iReadBufFill( 0 ),
-        iWriteBufFill( 0 )
+        iReadPos( 0 ),
+        iWriteBufFill( 0 ),
+        iWritePos( 0 )
 {
+        sReadBuf = new char[iBufSize];
+        sWriteBuf = new char[iBufSize];
 }
 
 Bu::Buffer::~Buffer()
 {
+        delete[] sReadBuf;
+        delete[] sWriteBuf;
 }
 
 void Bu::Buffer::start()
@@ -23,15 +36,118 @@ size_t Bu::Buffer::stop()
 {
 }
 
+void Bu::Buffer::fillReadBuf()
+{
+        if( iReadBufFill+iReadPos < iBufSize )
+        {
+                printf("Buffer: Attempting to read %db.\n", iBufSize-iReadBufFill-iReadPos );
+                iReadBufFill += rNext.read(
+                        sReadBuf+iReadPos+iReadBufFill,
+                        iBufSize-iReadBufFill-iReadPos
+                        );
+                printf("Buffer: Read from stream, %db now in buffer.\n", iReadBufFill );
+        }
+}
+
 size_t Bu::Buffer::read( void *pBuf, size_t nBytes )
 {
+        if( nBytes <= 0 )
+        {
+                fillReadBuf();
+                return 0;
+        }
+
+        size_t nTotRead = 0;
+//      fillReadBuf();
+
+        do
+        {
+                int iAmnt = nBytes-nTotRead;
+                if( iAmnt > iReadBufFill )
+                {
+                        iAmnt = iReadBufFill;
+                }
+                if( iAmnt > 0 )
+                {
+                        memcpy( ((char *)pBuf)+nTotRead, sReadBuf+iReadPos, iAmnt );
+                        iReadPos += iAmnt;
+                        nTotRead += iAmnt;
+                        iReadBufFill -= iAmnt;
+                }
+                if( iReadBufFill == 0 )
+                {
+                        iReadPos = 0;
+                        fillReadBuf();
+                }
+        }
+        while( nTotRead < nBytes && iReadBufFill > 0 );
+
+        printf("Buffer:  %db returned, %db remain in buffer.\n", nTotRead, iReadBufFill );
+
+        return nTotRead;
 }
 
 size_t Bu::Buffer::write( const void *pBuf, size_t nBytes )
 {
+        size_t nTotWrote = 0;
+
+        do
+        {
+                int iAmnt = nBytes-nTotWrote;
+                if( iAmnt > iBufSize-iWritePos-iWriteBufFill )
+                {
+                        iAmnt = iBufSize-iWritePos-iWriteBufFill;
+                }
+                if( iAmnt > 0 )
+                {
+                        memcpy(
+                                sWriteBuf+iWritePos+iWriteBufFill,
+                                ((char *)pBuf)+nTotWrote,
+                                iAmnt
+                                );
+                        nTotWrote += iAmnt;
+                        iWriteBufFill += iAmnt;
+                        printf("Buffer: Moved %db to write buffer, %db filled now.\n",
+                                        iAmnt, iWriteBufFill );
+                }
+                while( iWritePos+iWriteBufFill == iBufSize )
+                {
+                        printf("iWritePos = %d\n", iWritePos );
+                        int iWr = rNext.write( sWriteBuf+iWritePos, iWriteBufFill );
+                        printf("Buffer: Wrote %db from buffer to stream, %db filled now.\n", iWr, iWriteBufFill-iWr );
+                        if( iWr == 0 )
+                        {
+                                return nTotWrote;
+                        }
+                        else if( iWr == iWriteBufFill )
+                        {
+                                iWritePos = iWriteBufFill = 0;
+                        }
+                        else
+                        {
+                                iWritePos += iWr;
+                                iWriteBufFill -= iWr;
+                        }
+                }
+        }
+        while( nTotWrote < nBytes && iWriteBufFill < iBufSize+iWritePos );
+
+        return nTotWrote;
 }
 
 void Bu::Buffer::flush()
 {
+        if( iWriteBufFill > 0 )
+        {
+                printf("Buffer: Flushing remaining data, %db.\n", iWriteBufFill );
+                int iWr = 0;
+                do
+                {
+                        iWr = rNext.write( sWriteBuf+iWritePos, iWriteBufFill );
+                        printf("Buffer: %db written to stream.\n", iWr );
+                        iWritePos += iWr;
+                        iWriteBufFill -= iWr;
+                } while( iWriteBufFill > 0 && iWr > 0 );
+        }
 }