xwords/xwords4/common/strutils.c

/* -*-mode: C; compile-command: "cd ../linux && make MEMDEBUG=TRUE"; -*- */
/* 
 * Copyright 2001-2009 by Eric House (xwords@eehouse.org).  All rights
 * reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include "strutils.h"
#include "xwstream.h"
#include "mempool.h"
#include "xptypes.h"

#ifdef CPLUS
extern "C" {
#endif

XP_U16
bitsForMax( XP_U32 n )
{
    XP_U16 result = 0;
    XP_ASSERT( n > 0 );

    while ( n != 0 ) {
        n >>= 1;
        ++result;
    }

    return result;
} /* bitsForMax */

static void
tilesToStream( XWStreamCtxt* stream, const Tile* tiles, XP_U16 nTiles )
{
    while ( nTiles-- ) {
        stream_putBits( stream, TILE_NBITS, *tiles++ );
    }
} /* tilesToStream */

void
traySetToStream( XWStreamCtxt* stream, const TrayTileSet* ts )
{
    XP_U16 nTiles = ts->nTiles;
    stream_putBits( stream, NTILES_NBITS, nTiles );
    tilesToStream( stream, ts->tiles, nTiles );
} /* traySetFromStream */

static void
tilesFromStream( XWStreamCtxt* stream, Tile* tiles, XP_U16 nTiles )
{
    while ( nTiles-- ) {
        *tiles++ = (Tile)stream_getBits( stream, TILE_NBITS );
    }
} /* tilesFromStream */

void
traySetFromStream( XWStreamCtxt* stream, TrayTileSet* ts )
{
    XP_U16 nTiles = (XP_U16)stream_getBits( stream, NTILES_NBITS );
    tilesFromStream( stream, ts->tiles, nTiles );
    ts->nTiles = (XP_U8)nTiles;
} /* traySetFromStream */

#if 0
static void
signedToStream( XWStreamCtxt* stream, XP_U16 nBits, XP_S32 num )
{
    XP_Bool negative = num < 0;
    stream_putBits( stream, 1, negative );
    if ( negative ) {
        num *= -1;
    }
    stream_putBits( stream, nBits, num );
} /* signedToStream */

XP_S32
signedFromStream( XWStreamCtxt* stream, XP_U16 nBits )
{
    XP_S32 result;
    XP_Bool negative = stream_getBits( stream, 1 );
    result = stream_getBits( stream, nBits );
    if ( negative ) {
        result *= -1;
    }
    return result;
} /* signedFromStream */
#endif

XP_UCHAR*
p_stringFromStream( MPFORMAL XWStreamCtxt* stream
#ifdef MEM_DEBUG
                    , const char* file, XP_U32 lineNo 
#endif
                    )
{
    XP_UCHAR buf[0xFF];
    XP_UCHAR* str = (XP_UCHAR*)NULL;
    XP_U16 len = stringFromStreamHere( stream, buf, sizeof(buf) );

    if ( len > 0 ) {
#ifdef MEM_DEBUG
        str = mpool_alloc( mpool, len + 1, file, lineNo );
#else
        str = (XP_UCHAR*)XP_MALLOC( mpool, len + 1 ); /* leaked */
#endif
        XP_MEMCPY( str, buf, len + 1 );
    }
    return str;
} /* makeStringFromStream */

XP_U16
stringFromStreamHere( XWStreamCtxt* stream, XP_UCHAR* buf, XP_U16 buflen )
{
    XP_U16 len = stream_getU8( stream );
    if ( len > 0 ) {
        XP_ASSERT( len < buflen );
        if ( len >= buflen ) {
            /* better to leave stream in bad state than overwrite stack */
            len = buflen - 1;
        }
        stream_getBytes( stream, buf, len );
    }
    buf[len] = '\0';
    return len;
}

void
stringToStream( XWStreamCtxt* stream, const XP_UCHAR* str )
{
    XP_U16 len = str==NULL? 0: XP_STRLEN( (const char*)str );
    XP_ASSERT( len < 0xFF );
    stream_putU8( stream, (XP_U8)len );
    stream_putBytes( stream, str, len );
} /* putStringToStream */

/*****************************************************************************
 *
 ****************************************************************************/
XP_UCHAR* 
p_copyString( MPFORMAL const XP_UCHAR* instr
#ifdef MEM_DEBUG
            , const char* file, XP_U32 lineNo 
#endif
            )
{
    XP_UCHAR* result = (XP_UCHAR*)NULL;
    if ( !!instr ) {
        XP_U16 len = 1 + XP_STRLEN( (const char*)instr );
#ifdef MEM_DEBUG
        result = mpool_alloc( mpool, len, file, lineNo );
#else
        result = XP_MALLOC( ignore, len );
#endif

        XP_ASSERT( !!result );
        XP_MEMCPY( result, instr, len );
    }
    return result;
} /* copyString */

void
p_replaceStringIfDifferent( MPFORMAL XP_UCHAR** curLoc, const XP_UCHAR* newStr
#ifdef MEM_DEBUG
            , const char* file, XP_U32 lineNo 
#endif
                          )
{
    XP_UCHAR* curStr = *curLoc;

    if ( !!newStr && !!curStr && 
         (0 == XP_STRCMP( (const char*)curStr, (const char*)newStr ) ) ) {
        /* do nothing; we're golden */
    } else {
        if ( !!curStr ) {
            XP_FREE( mpool, curStr );
        }
#ifdef MEM_DEBUG
        curStr = p_copyString( mpool, newStr, file, lineNo );
#else
        curStr = p_copyString( newStr );
#endif
    }

    *curLoc = curStr;
} /* replaceStringIfDifferent */

/* 
 * A wrapper for printing etc. potentially null strings.
 */
XP_UCHAR* 
emptyStringIfNull( XP_UCHAR* str )
{
    return !!str? str : (XP_UCHAR*)"";
} /* emptyStringIfNull */

XP_Bool
randIntArray( XP_U16* rnums, XP_U16 count )
{
    XP_Bool changed = XP_FALSE;
    XP_U16 i;

    for ( i = 0; i < count; ++i ) {
        rnums[i] = i;
    }

    for ( i = count; i > 0 ; ) {
        XP_U16 rIndex = ((XP_U16)XP_RANDOM()) % i;
        if ( --i != rIndex ) {
            XP_U16 tmp = rnums[rIndex];
            rnums[rIndex] = rnums[i];
            rnums[i] = tmp;
            if ( !changed ) {
                changed = XP_TRUE;
            }
        }
    }

    return changed;
} /* randIntArray */

#ifdef XWFEATURE_SMS
/* base-64 encode binary data as a message legal for SMS.  See
 * http://www.ietf.org/rfc/rfc2045.txt for the algorithm.  glib uses this and
 * so it's not needed on linux, but unless all platforms provided identical
 * implementations it's needed for messages to be cross-platform.
*/

static const XP_UCHAR* 
getSMSTable( void )
{
    return "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
}
#define PADCHAR '='

static void
bitsToChars( const XP_U8* bytesIn, XP_U16 nValidBytes, XP_UCHAR* out, 
             XP_U16* outlen )
{
    XP_U16 nValidSextets = ((nValidBytes * 8) + 5) / 6; /* +5: round up */
    XP_U8 local[4] = { 0, 0, 0, 0 };
    XP_U16 bits[4];
    XP_MEMCPY( local, bytesIn, nValidBytes );
    /* top 6 bits of first byte */
    bits[0] = local[0] >> 2;
    /* bottom 2 bits of first byte, top four of second */ 
    bits[1] = ((local[0] << 4) & 0x30 ) | (local[1] >> 4);
    /* bottom four bits of second byte, top two of third */ 
    bits[2] = ((local[1] << 2) & 0x3C) | (local[2] >> 6);
    /* bottom six bits of third */
    bits[3] = local[2] & 0x3F;

    const XP_UCHAR* table = getSMSTable();

    XP_U16 ii;
    for ( ii = 0; ii < 4; ++ii ) {
        XP_UCHAR ch;
        if ( ii < nValidSextets ) {
            XP_U16 index = bits[ii];
            ch = table[index];
        } else {
            ch = PADCHAR;
        }
        out[(*outlen)++] = ch;
    }
} /* bitsToChars */

void
binToSms( XP_UCHAR* out, XP_U16* outlenp, const XP_U8* in, const XP_U16 inlen )
{
    XP_U16 inConsumed;
    XP_U16 outlen = 0;

    for ( inConsumed = 0; ; /*inConsumed += 3*/ ) {
        XP_U16 validBytes = XP_MIN( 3, inlen - inConsumed );
        bitsToChars( &in[inConsumed], validBytes, out, &outlen );
        XP_ASSERT( outlen <= *outlenp );

        inConsumed += 3;
        if ( inConsumed >= inlen ) {
            break;
        }
    }
    XP_ASSERT( outlen < *outlenp );
    out[outlen] = '\0';
    *outlenp = outlen;
    XP_ASSERT( *outlenp >= inlen );
} /* binToSms */

/* Return false if illegal, e.g. contains bad characters.
 */

static XP_U8
findRank( XP_UCHAR ch )
{
    XP_U8 rank;
    if ( ch == PADCHAR ) {
        rank = 0;
    } else {
        const XP_UCHAR* table = getSMSTable();
        for ( rank = 0; rank < 64; ++rank ) {
            if ( table[rank] == ch ) {
                break;
            }
        }
        XP_ASSERT( rank < 64 );
    }
    return rank;
}

/* This function stolen from glib file glib/gbase64.c.  It's also GPL'd, so
 * that may not matter.  But does my copyright need to change?  PENDING
 *
 * Also, need to check there's space before writing!  PENDING
 */
XP_Bool
smsToBin( XP_U8* out, XP_U16* outlenp, const XP_UCHAR* sms, XP_U16 smslen )
{
    const XP_UCHAR* inptr;
    XP_U8* outptr = out;
    const XP_UCHAR* smsend = sms + smslen;
    XP_U8 ch, rank;
    XP_U8 last[2];
    unsigned int vv = 0;
    int ii = 0;

    inptr = sms;
    last[0] = last[1] = 0;
    while ( inptr < smsend ) {
        ch = *inptr++;
        rank = findRank( ch );

        last[1] = last[0];
        last[0] = ch;
        vv = (vv<<6) | rank;
        if ( ++ii == 4 ) {
            *outptr++ = vv >> 16;
            if (last[1] != PADCHAR ) {
                *outptr++ = vv >> 8;
            }
            if (last[0] != PADCHAR ) {
                *outptr++ = vv;
            }
            ii = 0;
	    }
    }

    XP_ASSERT( *outlenp >= (outptr - out) );
    *outlenp = outptr - out;

    return XP_TRUE;
} /* smsToBin */

#endif

#ifdef DEBUG
#define NUM_PER_LINE 8
void
log_hex( const XP_U8* memp, XP_U16 len, const char* tag )
{
    const char* hex = "0123456789ABCDEF";
    XP_U16 i, j;
    XP_U16 offset = 0;

    while ( offset < len ) {
        XP_UCHAR buf[128];
        XP_UCHAR vals[NUM_PER_LINE*3];
        XP_UCHAR* valsp = vals;
        XP_UCHAR chars[NUM_PER_LINE+1];
        XP_UCHAR* charsp = chars;
        XP_U16 oldOffset = offset;

        for ( i = 0; i < NUM_PER_LINE && offset < len; ++i ) {
            XP_U8 byte = memp[offset];
            for ( j = 0; j < 2; ++j ) {
                *valsp++ = hex[(byte & 0xF0) >> 4];
                byte <<= 4;
            }
            *valsp++ = ':';

            byte = memp[offset];
            if ( (byte >= 'A' && byte <= 'Z')
                 || (byte >= 'a' && byte <= 'z')
                 || (byte >= '0' && byte <= '9') ) {
                /* keep it */
            } else {
                byte = '.';
            }
            *charsp++ = byte;
            ++offset;
        }
        *(valsp-1) = '\0';      /* -1 to overwrite ':' */
        *charsp = '\0';

        if ( (NULL == tag) || (XP_STRLEN(tag) + sizeof(vals) >= sizeof(buf)) ) {
            tag = "<tag>";
        }
        XP_SNPRINTF( buf, sizeof(buf), "%s[%d]: %s %s", tag, oldOffset, 
                     vals, chars );
        XP_LOGF( "%s", buf );
    }
}
#endif

#ifdef CPLUS
}
#endif