Added a new enum value to Bu::File, Bu::File::WriteNew which combines Write,

Truncate, and Create, the flags used most commonly when writing a new file.

Also added the Bu::Base64 filter class, it does base64 encoding and decoding,
it may need a couple more interfaces added, but for the most part, it's solid.

1 files changed, 132 insertions, 0 deletions

diff --git a/src/base64.cpp b/src/base64.cpp
new file mode 100644
index 0000000..723788b
--- /dev/null
+++ b/src/base64.cpp
@@ -0,0 +1,132 @@
+#include "bu/base64.h"
+
+const char Bu::Base64::tblEnc[65] = {
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+};
+
+Bu::Base64::Base64( Bu::Stream &rNext, Mode eMode ) :
+        Bu::Filter( rNext ),
+        iBPos( 0 ),
+        iBuf( 0 ),
+        iTotalIn( 0 ),
+        iTotalOut( 0 ),
+        eMode( eMode )
+{
+        start();
+
+        memset( tblDec, 0, 80 );
+        for( int j = 0; j < 64; j++ )
+        {
+                tblDec[tblEnc[j]-'+'] = j;
+        //      printf("'%c' = %d\n", tblEnc[j], j );
+        }
+        /*
+        for( int j = 0; j < 64; j++ )
+        {
+                printf("'%c' = '%c' (%d = %d)\n",
+                        tblEnc[j], tblEnc[tblDec[tblEnc[j]-'+']],
+                        j, tblDec[tblEnc[j]-'+'] );
+        }*/
+
+        // The following is used to compute the table size for the decoding table.
+        /*
+        char low='A', high='A';
+        for( int j = 0; j < 64; j++ )
+        {
+                if( tblEnc[j] < low )
+                        low = tblEnc[j];
+                if( tblEnc[j] > high )
+                        high = tblEnc[j];
+        }
+
+        printf("'%c' - '%c' (%d - %d) (%d)\n", low, high, low, high, high-low );
+        */
+}
+
+Bu::Base64::~Base64()
+{
+        stop();
+}
+
+void Bu::Base64::start()
+{
+}
+
+size_t Bu::Base64::stop()
+{
+        if( eMode == Write )
+        {
+                char outBuf[4];
+                int iBUsed = 4-(3-iBPos);
+                if( iBPos == 0 )
+                        return iTotalOut;
+                for( int k = 0; k < 4; k++ )
+                {
+                        outBuf[3-k] = tblEnc[(iBuf>>(6*k))&0x3f];
+                }
+                for( int k = iBUsed; k < 4; k++ )
+                {
+                        outBuf[k] = '=';
+                }
+                iTotalOut += rNext.write( outBuf, 4 );
+                return iTotalOut;
+        }
+        else
+        {
+                return iTotalIn;
+        }
+}
+
+size_t Bu::Base64::read( void *pBuf, size_t nBytes )
+{
+        size_t sIn = 0;
+        char buf[4];
+        while( sIn < nBytes )
+        {
+                if( rNext.read( buf, 4 ) == 0 )
+                        return sIn;
+                int iChars = 3;
+                for( int j = 0; j < 4; j++ )
+                {
+                        if( buf[j] == '=' )
+                                iChars--;
+                        else
+                                iBuf |= (tblDec[buf[j]-'+']&0x3f)<<((3-j)*6);
+                        printf("%d:  %06X (%02X)\n", j, iBuf, (tblDec[buf[j]-'+']&0x3f) );
+                }
+                for( int j = 0; j < iChars; j++ )
+                {
+                        ((unsigned char *)pBuf)[sIn++] = (iBuf>>(8*(2-j)))&0xFF;
+                }
+                iBuf = 0;
+        }
+
+        return sIn;
+}
+
+size_t Bu::Base64::write( const void *pBuf, size_t nBytes )
+{
+        size_t sOut = 0;
+        char outBuf[4];
+        for( size_t j = 0; j < nBytes; j++ )
+        {
+                iBuf |= (((uint8_t *)pBuf)[j])<<((2-iBPos++)*8);
+                if( iBPos == 3 )
+                {
+                        for( int k = 0; k < 4; k++ )
+                        {
+                                outBuf[3-k] = tblEnc[(iBuf>>(6*k))&0x3f];
+                        }
+                        sOut += rNext.write( outBuf, 4 );
+                        iBPos = iBuf = 0;
+                }
+        }
+        iTotalOut += sOut;
+        return sOut;
+}
+
+bool Bu::Base64::isOpen()
+{
+        return true;
+}
+