decompress.c
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上传日期:2007-06-13
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文件大小:21k
- /*
- * ===========================================================================
- * PRODUCTION $Log: decompress.c,v $
- * PRODUCTION Revision 1000.0 2003/10/29 15:44:01 gouriano
- * PRODUCTION PRODUCTION: IMPORTED [ORIGINAL] Dev-tree R1.1
- * PRODUCTION
- * ===========================================================================
- */
- /*-------------------------------------------------------------*/
- /*--- Decompression machinery ---*/
- /*--- decompress.c ---*/
- /*-------------------------------------------------------------*/
- /*--
- This file is a part of bzip2 and/or libbzip2, a program and
- library for lossless, block-sorting data compression.
- Copyright (C) 1996-2002 Julian R Seward. All rights reserved.
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
- 1. Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- 2. The origin of this software must not be misrepresented; you must
- not claim that you wrote the original software. If you use this
- software in a product, an acknowledgment in the product
- documentation would be appreciated but is not required.
- 3. Altered source versions must be plainly marked as such, and must
- not be misrepresented as being the original software.
- 4. The name of the author may not be used to endorse or promote
- products derived from this software without specific prior written
- permission.
- THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
- OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
- GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- Julian Seward, Cambridge, UK.
- jseward@acm.org
- bzip2/libbzip2 version 1.0 of 21 March 2000
- This program is based on (at least) the work of:
- Mike Burrows
- David Wheeler
- Peter Fenwick
- Alistair Moffat
- Radford Neal
- Ian H. Witten
- Robert Sedgewick
- Jon L. Bentley
- For more information on these sources, see the manual.
- --*/
- #include "bzlib_private.h"
- /*---------------------------------------------------*/
- static
- void makeMaps_d ( DState* s )
- {
- Int32 i;
- s->nInUse = 0;
- for (i = 0; i < 256; i++)
- if (s->inUse[i]) {
- s->seqToUnseq[s->nInUse] = i;
- s->nInUse++;
- }
- }
- /*---------------------------------------------------*/
- #define RETURN(rrr)
- { retVal = rrr; goto save_state_and_return; };
- #define GET_BITS(lll,vvv,nnn)
- case lll: s->state = lll;
- while (True) {
- if (s->bsLive >= nnn) {
- UInt32 v;
- v = (s->bsBuff >>
- (s->bsLive-nnn)) & ((1 << nnn)-1);
- s->bsLive -= nnn;
- vvv = v;
- break;
- }
- if (s->strm->avail_in == 0) RETURN(BZ_OK);
- s->bsBuff
- = (s->bsBuff << 8) |
- ((UInt32)
- (*((UChar*)(s->strm->next_in))));
- s->bsLive += 8;
- s->strm->next_in++;
- s->strm->avail_in--;
- s->strm->total_in_lo32++;
- if (s->strm->total_in_lo32 == 0)
- s->strm->total_in_hi32++;
- }
- #define GET_UCHAR(lll,uuu)
- GET_BITS(lll,uuu,8)
- #define GET_BIT(lll,uuu)
- GET_BITS(lll,uuu,1)
- /*---------------------------------------------------*/
- #define GET_MTF_VAL(label1,label2,lval)
- {
- if (groupPos == 0) {
- groupNo++;
- if (groupNo >= nSelectors)
- RETURN(BZ_DATA_ERROR);
- groupPos = BZ_G_SIZE;
- gSel = s->selector[groupNo];
- gMinlen = s->minLens[gSel];
- gLimit = &(s->limit[gSel][0]);
- gPerm = &(s->perm[gSel][0]);
- gBase = &(s->base[gSel][0]);
- }
- groupPos--;
- zn = gMinlen;
- GET_BITS(label1, zvec, zn);
- while (1) {
- if (zn > 20 /* the longest code */)
- RETURN(BZ_DATA_ERROR);
- if (zvec <= gLimit[zn]) break;
- zn++;
- GET_BIT(label2, zj);
- zvec = (zvec << 1) | zj;
- };
- if (zvec - gBase[zn] < 0
- || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE)
- RETURN(BZ_DATA_ERROR);
- lval = gPerm[zvec - gBase[zn]];
- }
- /*---------------------------------------------------*/
- Int32 BZ2_decompress ( DState* s )
- {
- UChar uc;
- Int32 retVal;
- Int32 minLen, maxLen;
- bz_stream* strm = s->strm;
- /* stuff that needs to be saved/restored */
- Int32 i;
- Int32 j;
- Int32 t;
- Int32 alphaSize;
- Int32 nGroups;
- Int32 nSelectors;
- Int32 EOB;
- Int32 groupNo;
- Int32 groupPos;
- Int32 nextSym;
- Int32 nblockMAX;
- Int32 nblock;
- Int32 es;
- Int32 N;
- Int32 curr;
- Int32 zt;
- Int32 zn;
- Int32 zvec;
- Int32 zj;
- Int32 gSel;
- Int32 gMinlen;
- Int32* gLimit;
- Int32* gBase;
- Int32* gPerm;
- if (s->state == BZ_X_MAGIC_1) {
- /*initialise the save area*/
- s->save_i = 0;
- s->save_j = 0;
- s->save_t = 0;
- s->save_alphaSize = 0;
- s->save_nGroups = 0;
- s->save_nSelectors = 0;
- s->save_EOB = 0;
- s->save_groupNo = 0;
- s->save_groupPos = 0;
- s->save_nextSym = 0;
- s->save_nblockMAX = 0;
- s->save_nblock = 0;
- s->save_es = 0;
- s->save_N = 0;
- s->save_curr = 0;
- s->save_zt = 0;
- s->save_zn = 0;
- s->save_zvec = 0;
- s->save_zj = 0;
- s->save_gSel = 0;
- s->save_gMinlen = 0;
- s->save_gLimit = NULL;
- s->save_gBase = NULL;
- s->save_gPerm = NULL;
- }
- /*restore from the save area*/
- i = s->save_i;
- j = s->save_j;
- t = s->save_t;
- alphaSize = s->save_alphaSize;
- nGroups = s->save_nGroups;
- nSelectors = s->save_nSelectors;
- EOB = s->save_EOB;
- groupNo = s->save_groupNo;
- groupPos = s->save_groupPos;
- nextSym = s->save_nextSym;
- nblockMAX = s->save_nblockMAX;
- nblock = s->save_nblock;
- es = s->save_es;
- N = s->save_N;
- curr = s->save_curr;
- zt = s->save_zt;
- zn = s->save_zn;
- zvec = s->save_zvec;
- zj = s->save_zj;
- gSel = s->save_gSel;
- gMinlen = s->save_gMinlen;
- gLimit = s->save_gLimit;
- gBase = s->save_gBase;
- gPerm = s->save_gPerm;
- retVal = BZ_OK;
- switch (s->state) {
- GET_UCHAR(BZ_X_MAGIC_1, uc);
- if (uc != BZ_HDR_B) RETURN(BZ_DATA_ERROR_MAGIC);
- GET_UCHAR(BZ_X_MAGIC_2, uc);
- if (uc != BZ_HDR_Z) RETURN(BZ_DATA_ERROR_MAGIC);
- GET_UCHAR(BZ_X_MAGIC_3, uc)
- if (uc != BZ_HDR_h) RETURN(BZ_DATA_ERROR_MAGIC);
- GET_BITS(BZ_X_MAGIC_4, s->blockSize100k, 8)
- if (s->blockSize100k < (BZ_HDR_0 + 1) ||
- s->blockSize100k > (BZ_HDR_0 + 9)) RETURN(BZ_DATA_ERROR_MAGIC);
- s->blockSize100k -= BZ_HDR_0;
- if (s->smallDecompress) {
- s->ll16 = BZALLOC( s->blockSize100k * 100000 * sizeof(UInt16) );
- s->ll4 = BZALLOC(
- ((1 + s->blockSize100k * 100000) >> 1) * sizeof(UChar)
- );
- if (s->ll16 == NULL || s->ll4 == NULL) RETURN(BZ_MEM_ERROR);
- } else {
- s->tt = BZALLOC( s->blockSize100k * 100000 * sizeof(Int32) );
- if (s->tt == NULL) RETURN(BZ_MEM_ERROR);
- }
- GET_UCHAR(BZ_X_BLKHDR_1, uc);
- if (uc == 0x17) goto endhdr_2;
- if (uc != 0x31) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_BLKHDR_2, uc);
- if (uc != 0x41) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_BLKHDR_3, uc);
- if (uc != 0x59) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_BLKHDR_4, uc);
- if (uc != 0x26) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_BLKHDR_5, uc);
- if (uc != 0x53) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_BLKHDR_6, uc);
- if (uc != 0x59) RETURN(BZ_DATA_ERROR);
- s->currBlockNo++;
- if (s->verbosity >= 2)
- VPrintf1 ( "n [%d: huff+mtf ", s->currBlockNo );
-
- s->storedBlockCRC = 0;
- GET_UCHAR(BZ_X_BCRC_1, uc);
- s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
- GET_UCHAR(BZ_X_BCRC_2, uc);
- s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
- GET_UCHAR(BZ_X_BCRC_3, uc);
- s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
- GET_UCHAR(BZ_X_BCRC_4, uc);
- s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
- GET_BITS(BZ_X_RANDBIT, s->blockRandomised, 1);
- s->origPtr = 0;
- GET_UCHAR(BZ_X_ORIGPTR_1, uc);
- s->origPtr = (s->origPtr << 8) | ((Int32)uc);
- GET_UCHAR(BZ_X_ORIGPTR_2, uc);
- s->origPtr = (s->origPtr << 8) | ((Int32)uc);
- GET_UCHAR(BZ_X_ORIGPTR_3, uc);
- s->origPtr = (s->origPtr << 8) | ((Int32)uc);
- if (s->origPtr < 0)
- RETURN(BZ_DATA_ERROR);
- if (s->origPtr > 10 + 100000*s->blockSize100k)
- RETURN(BZ_DATA_ERROR);
- /*--- Receive the mapping table ---*/
- for (i = 0; i < 16; i++) {
- GET_BIT(BZ_X_MAPPING_1, uc);
- if (uc == 1)
- s->inUse16[i] = True; else
- s->inUse16[i] = False;
- }
- for (i = 0; i < 256; i++) s->inUse[i] = False;
- for (i = 0; i < 16; i++)
- if (s->inUse16[i])
- for (j = 0; j < 16; j++) {
- GET_BIT(BZ_X_MAPPING_2, uc);
- if (uc == 1) s->inUse[i * 16 + j] = True;
- }
- makeMaps_d ( s );
- if (s->nInUse == 0) RETURN(BZ_DATA_ERROR);
- alphaSize = s->nInUse+2;
- /*--- Now the selectors ---*/
- GET_BITS(BZ_X_SELECTOR_1, nGroups, 3);
- if (nGroups < 2 || nGroups > 6) RETURN(BZ_DATA_ERROR);
- GET_BITS(BZ_X_SELECTOR_2, nSelectors, 15);
- if (nSelectors < 1) RETURN(BZ_DATA_ERROR);
- for (i = 0; i < nSelectors; i++) {
- j = 0;
- while (True) {
- GET_BIT(BZ_X_SELECTOR_3, uc);
- if (uc == 0) break;
- j++;
- if (j >= nGroups) RETURN(BZ_DATA_ERROR);
- }
- s->selectorMtf[i] = j;
- }
- /*--- Undo the MTF values for the selectors. ---*/
- {
- UChar pos[BZ_N_GROUPS], tmp, v;
- for (v = 0; v < nGroups; v++) pos[v] = v;
-
- for (i = 0; i < nSelectors; i++) {
- v = s->selectorMtf[i];
- tmp = pos[v];
- while (v > 0) { pos[v] = pos[v-1]; v--; }
- pos[0] = tmp;
- s->selector[i] = tmp;
- }
- }
- /*--- Now the coding tables ---*/
- for (t = 0; t < nGroups; t++) {
- GET_BITS(BZ_X_CODING_1, curr, 5);
- for (i = 0; i < alphaSize; i++) {
- while (True) {
- if (curr < 1 || curr > 20) RETURN(BZ_DATA_ERROR);
- GET_BIT(BZ_X_CODING_2, uc);
- if (uc == 0) break;
- GET_BIT(BZ_X_CODING_3, uc);
- if (uc == 0) curr++; else curr--;
- }
- s->len[t][i] = curr;
- }
- }
- /*--- Create the Huffman decoding tables ---*/
- for (t = 0; t < nGroups; t++) {
- minLen = 32;
- maxLen = 0;
- for (i = 0; i < alphaSize; i++) {
- if (s->len[t][i] > maxLen) maxLen = s->len[t][i];
- if (s->len[t][i] < minLen) minLen = s->len[t][i];
- }
- BZ2_hbCreateDecodeTables (
- &(s->limit[t][0]),
- &(s->base[t][0]),
- &(s->perm[t][0]),
- &(s->len[t][0]),
- minLen, maxLen, alphaSize
- );
- s->minLens[t] = minLen;
- }
- /*--- Now the MTF values ---*/
- EOB = s->nInUse+1;
- nblockMAX = 100000 * s->blockSize100k;
- groupNo = -1;
- groupPos = 0;
- for (i = 0; i <= 255; i++) s->unzftab[i] = 0;
- /*-- MTF init --*/
- {
- Int32 ii, jj, kk;
- kk = MTFA_SIZE-1;
- for (ii = 256 / MTFL_SIZE - 1; ii >= 0; ii--) {
- for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
- s->mtfa[kk] = (UChar)(ii * MTFL_SIZE + jj);
- kk--;
- }
- s->mtfbase[ii] = kk + 1;
- }
- }
- /*-- end MTF init --*/
- nblock = 0;
- GET_MTF_VAL(BZ_X_MTF_1, BZ_X_MTF_2, nextSym);
- while (True) {
- if (nextSym == EOB) break;
- if (nextSym == BZ_RUNA || nextSym == BZ_RUNB) {
- es = -1;
- N = 1;
- do {
- if (nextSym == BZ_RUNA) es = es + (0+1) * N; else
- if (nextSym == BZ_RUNB) es = es + (1+1) * N;
- N = N * 2;
- GET_MTF_VAL(BZ_X_MTF_3, BZ_X_MTF_4, nextSym);
- }
- while (nextSym == BZ_RUNA || nextSym == BZ_RUNB);
- es++;
- uc = s->seqToUnseq[ s->mtfa[s->mtfbase[0]] ];
- s->unzftab[uc] += es;
- if (s->smallDecompress)
- while (es > 0) {
- if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
- s->ll16[nblock] = (UInt16)uc;
- nblock++;
- es--;
- }
- else
- while (es > 0) {
- if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
- s->tt[nblock] = (UInt32)uc;
- nblock++;
- es--;
- };
- continue;
- } else {
- if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
- /*-- uc = MTF ( nextSym-1 ) --*/
- {
- Int32 ii, jj, kk, pp, lno, off;
- UInt32 nn;
- nn = (UInt32)(nextSym - 1);
- if (nn < MTFL_SIZE) {
- /* avoid general-case expense */
- pp = s->mtfbase[0];
- uc = s->mtfa[pp+nn];
- while (nn > 3) {
- Int32 z = pp+nn;
- s->mtfa[(z) ] = s->mtfa[(z)-1];
- s->mtfa[(z)-1] = s->mtfa[(z)-2];
- s->mtfa[(z)-2] = s->mtfa[(z)-3];
- s->mtfa[(z)-3] = s->mtfa[(z)-4];
- nn -= 4;
- }
- while (nn > 0) {
- s->mtfa[(pp+nn)] = s->mtfa[(pp+nn)-1]; nn--;
- };
- s->mtfa[pp] = uc;
- } else {
- /* general case */
- lno = nn / MTFL_SIZE;
- off = nn % MTFL_SIZE;
- pp = s->mtfbase[lno] + off;
- uc = s->mtfa[pp];
- while (pp > s->mtfbase[lno]) {
- s->mtfa[pp] = s->mtfa[pp-1]; pp--;
- };
- s->mtfbase[lno]++;
- while (lno > 0) {
- s->mtfbase[lno]--;
- s->mtfa[s->mtfbase[lno]]
- = s->mtfa[s->mtfbase[lno-1] + MTFL_SIZE - 1];
- lno--;
- }
- s->mtfbase[0]--;
- s->mtfa[s->mtfbase[0]] = uc;
- if (s->mtfbase[0] == 0) {
- kk = MTFA_SIZE-1;
- for (ii = 256 / MTFL_SIZE-1; ii >= 0; ii--) {
- for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
- s->mtfa[kk] = s->mtfa[s->mtfbase[ii] + jj];
- kk--;
- }
- s->mtfbase[ii] = kk + 1;
- }
- }
- }
- }
- /*-- end uc = MTF ( nextSym-1 ) --*/
- s->unzftab[s->seqToUnseq[uc]]++;
- if (s->smallDecompress)
- s->ll16[nblock] = (UInt16)(s->seqToUnseq[uc]); else
- s->tt[nblock] = (UInt32)(s->seqToUnseq[uc]);
- nblock++;
- GET_MTF_VAL(BZ_X_MTF_5, BZ_X_MTF_6, nextSym);
- continue;
- }
- }
- /* Now we know what nblock is, we can do a better sanity
- check on s->origPtr.
- */
- if (s->origPtr < 0 || s->origPtr >= nblock)
- RETURN(BZ_DATA_ERROR);
- s->state_out_len = 0;
- s->state_out_ch = 0;
- BZ_INITIALISE_CRC ( s->calculatedBlockCRC );
- s->state = BZ_X_OUTPUT;
- if (s->verbosity >= 2) VPrintf0 ( "rt+rld" );
- /*-- Set up cftab to facilitate generation of T^(-1) --*/
- s->cftab[0] = 0;
- for (i = 1; i <= 256; i++) s->cftab[i] = s->unzftab[i-1];
- for (i = 1; i <= 256; i++) s->cftab[i] += s->cftab[i-1];
- if (s->smallDecompress) {
- /*-- Make a copy of cftab, used in generation of T --*/
- for (i = 0; i <= 256; i++) s->cftabCopy[i] = s->cftab[i];
- /*-- compute the T vector --*/
- for (i = 0; i < nblock; i++) {
- uc = (UChar)(s->ll16[i]);
- SET_LL(i, s->cftabCopy[uc]);
- s->cftabCopy[uc]++;
- }
- /*-- Compute T^(-1) by pointer reversal on T --*/
- i = s->origPtr;
- j = GET_LL(i);
- do {
- Int32 tmp = GET_LL(j);
- SET_LL(j, i);
- i = j;
- j = tmp;
- }
- while (i != s->origPtr);
- s->tPos = s->origPtr;
- s->nblock_used = 0;
- if (s->blockRandomised) {
- BZ_RAND_INIT_MASK;
- BZ_GET_SMALL(s->k0); s->nblock_used++;
- BZ_RAND_UPD_MASK; s->k0 ^= BZ_RAND_MASK;
- } else {
- BZ_GET_SMALL(s->k0); s->nblock_used++;
- }
- } else {
- /*-- compute the T^(-1) vector --*/
- for (i = 0; i < nblock; i++) {
- uc = (UChar)(s->tt[i] & 0xff);
- s->tt[s->cftab[uc]] |= (i << 8);
- s->cftab[uc]++;
- }
- s->tPos = s->tt[s->origPtr] >> 8;
- s->nblock_used = 0;
- if (s->blockRandomised) {
- BZ_RAND_INIT_MASK;
- BZ_GET_FAST(s->k0); s->nblock_used++;
- BZ_RAND_UPD_MASK; s->k0 ^= BZ_RAND_MASK;
- } else {
- BZ_GET_FAST(s->k0); s->nblock_used++;
- }
- }
- RETURN(BZ_OK);
- endhdr_2:
- GET_UCHAR(BZ_X_ENDHDR_2, uc);
- if (uc != 0x72) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_ENDHDR_3, uc);
- if (uc != 0x45) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_ENDHDR_4, uc);
- if (uc != 0x38) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_ENDHDR_5, uc);
- if (uc != 0x50) RETURN(BZ_DATA_ERROR);
- GET_UCHAR(BZ_X_ENDHDR_6, uc);
- if (uc != 0x90) RETURN(BZ_DATA_ERROR);
- s->storedCombinedCRC = 0;
- GET_UCHAR(BZ_X_CCRC_1, uc);
- s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
- GET_UCHAR(BZ_X_CCRC_2, uc);
- s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
- GET_UCHAR(BZ_X_CCRC_3, uc);
- s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
- GET_UCHAR(BZ_X_CCRC_4, uc);
- s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
- s->state = BZ_X_IDLE;
- RETURN(BZ_STREAM_END);
- default: AssertH ( False, 4001 );
- }
- AssertH ( False, 4002 );
- save_state_and_return:
- s->save_i = i;
- s->save_j = j;
- s->save_t = t;
- s->save_alphaSize = alphaSize;
- s->save_nGroups = nGroups;
- s->save_nSelectors = nSelectors;
- s->save_EOB = EOB;
- s->save_groupNo = groupNo;
- s->save_groupPos = groupPos;
- s->save_nextSym = nextSym;
- s->save_nblockMAX = nblockMAX;
- s->save_nblock = nblock;
- s->save_es = es;
- s->save_N = N;
- s->save_curr = curr;
- s->save_zt = zt;
- s->save_zn = zn;
- s->save_zvec = zvec;
- s->save_zj = zj;
- s->save_gSel = gSel;
- s->save_gMinlen = gMinlen;
- s->save_gLimit = gLimit;
- s->save_gBase = gBase;
- s->save_gPerm = gPerm;
- return retVal;
- }
- /*-------------------------------------------------------------*/
- /*--- end decompress.c ---*/
- /*-------------------------------------------------------------*/