lib/bitio.c

   1 /*  bitio.c
   2     part of swftools
   3     implementation of bitio.h.
   4
   5     Copyright (C) 2003 Matthias Kramm <kramm@quiss.org>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #ifdef HAVE_UNISTD_H
  24 #include <unistd.h>
  25 #endif
  26 #ifdef HAVE_IO_H
  27 #include <io.h>
  28 #endif
  29 #include <string.h>
  30 #include <memory.h>
  31 #include <fcntl.h>
  32
  33 #include "../config.h"
  34
  35 #ifdef HAVE_ZLIB
  36 #include <zlib.h>
  37 #define ZLIB_BUFFER_SIZE 16384
  38 #endif
  39 #include "./bitio.h"
  40
  41 /* ---------------------------- null reader ------------------------------- */
  42
  43 static int reader_nullread(reader_t*r, void* data, int len)
  44 {
  45     memset(data, 0, len);
  46     return len;
  47 }
  48 static void reader_nullread_dealloc(reader_t*r)
  49 {
  50     memset(r, 0, sizeof(reader_t));
  51 }
  52 void reader_init_nullreader(reader_t*r)
  53 {
  54     r->read = reader_nullread;
  55     r->dealloc = reader_nullread_dealloc;
  56     r->internal = 0;
  57     r->type = READER_TYPE_NULL;
  58     r->mybyte = 0;
  59     r->bitpos = 8;
  60     r->pos = 0;
  61 }
  62 /* ---------------------------- file reader ------------------------------- */
  63
  64 static int reader_fileread(reader_t*reader, void* data, int len)
  65 {
  66     int ret = read((int)reader->internal, data, len);
  67     if(ret>=0)
  68         reader->pos += ret;
  69     return ret;
  70 }
  71 void reader_init_filereader(reader_t*r, int handle)
  72 {
  73     r->read = reader_fileread;
  74     r->internal = (void*)handle;
  75     r->type = READER_TYPE_FILE;
  76     r->mybyte = 0;
  77     r->bitpos = 8;
  78     r->pos = 0;
  79 }
  80
  81 /* ---------------------------- mem reader ------------------------------- */
  82
  83 struct memread_t
  84 {
  85     unsigned char*data;
  86     int length;
  87 };
  88 static int reader_memread(reader_t*reader, void* data, int len)
  89 {
  90     struct memread_t*mr = (struct memread_t*)reader->internal;
  91
  92     if(mr->length - reader->pos > len) {
  93         memcpy(data, &mr->data[reader->pos], len);
  94         reader->pos += len;
  95         return len;
  96     } else {
  97         memcpy(data, &mr->data[reader->pos], mr->length - reader->pos);
  98         reader->pos += mr->length;
  99         return mr->length - reader->pos;
 100     }
 101 }
 102 static void reader_memread_dealloc(reader_t*reader)
 103 {
 104     if(reader->internal)
 105         free(reader->internal);
 106     memset(reader, 0, sizeof(reader_t));
 107 }
 108 void reader_init_memreader(reader_t*r, void*newdata, int newlength)
 109 {
 110     struct memread_t*mr = (struct memread_t*)malloc(sizeof(struct memread_t));
 111     mr->data = (unsigned char*)newdata;
 112     mr->length = newlength;
 113     r->read = reader_memread;
 114     r->dealloc = reader_memread_dealloc;
 115     r->internal = (void*)mr;
 116     r->type = READER_TYPE_MEM;
 117     r->mybyte = 0;
 118     r->bitpos = 8;
 119     r->pos = 0;
 120 }
 121
 122 /* ---------------------------- mem writer ------------------------------- */
 123
 124 struct memwrite_t
 125 {
 126     unsigned char*data;
 127     int length;
 128 };
 129
 130 static int writer_memwrite_write(writer_t*w, void* data, int len)
 131 {
 132     struct memwrite_t*mw = (struct memwrite_t*)w->internal;
 133     if(mw->length - w->pos > len) {
 134         memcpy(&mw->data[w->pos], data, len);
 135         w->pos += len;
 136         return len;
 137     } else {
 138         memcpy(&mw->data[w->pos], data, mw->length - w->pos);
 139         w->pos = mw->length;
 140         return mw->length - w->pos;
 141     }
 142 }
 143 static void writer_memwrite_finish(writer_t*w)
 144 {
 145     if(w->internal)
 146         free(w->internal);
 147     w->internal = 0;
 148 }
 149 void writer_init_memwriter(writer_t*w, void*data, int len)
 150 {
 151     struct memwrite_t *mr;
 152     mr = (memwrite_t *)malloc(sizeof(struct memwrite_t));
 153     mr->data = (unsigned char *)data;
 154     mr->length = len;
 155     memset(w, 0, sizeof(writer_t));
 156     w->write = writer_memwrite_write;
 157     w->finish = writer_memwrite_finish;
 158     w->internal = (void*)mr;
 159     w->type = WRITER_TYPE_MEM;
 160     w->bitpos = 0;
 161     w->mybyte = 0;
 162     w->pos = 0;
 163 }
 164
 165 /* ------------------------- growing mem writer ------------------------------- */
 166
 167 struct growmemwrite_t
 168 {
 169     unsigned char*data;
 170     int length;
 171     U32 grow;
 172 };
 173 static int writer_growmemwrite_write(writer_t*w, void* data, int len)
 174 {
 175     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 176     if(!mw->data) {
 177         fprintf(stderr, "Illegal write operation: data already given away");
 178         exit(1);
 179     }
 180     if(mw->length - w->pos < len) {
 181         unsigned char*newmem;
 182         int newlength = mw->length;
 183         while(newlength - w->pos < len) {
 184             newlength += mw->grow;
 185         }
 186 #ifdef NO_REALLOC
 187         newmem = (unsigned char*)malloc(newlength);
 188         memcpy(newmem, mw->data, mw->length);
 189         free(mw->data);
 190         mw->data = newmem;
 191 #else
 192         mw->data = (unsigned char*)realloc(mw->data, newlength);
 193 #endif
 194         mw->length = newlength;
 195     }
 196     memcpy(&mw->data[w->pos], data, len);
 197     w->pos += len;
 198     return len;
 199 }
 200 static void writer_growmemwrite_finish(writer_t*w)
 201 {
 202     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 203     if(mw->data)
 204         free(mw->data);
 205     mw->data = 0;
 206     mw->length = 0;
 207     free(w->internal);mw=0;
 208     memset(w, 0, sizeof(writer_t));
 209 }
 210 void* writer_growmemwrite_getmem(writer_t*w)
 211 {
 212     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 213     void*ret = mw->data;
 214     /* remove own reference so that neither write() nor finish() can free it.
 215        It's property of the caller now.
 216     */
 217     mw->data = 0;
 218     return ret;
 219 }
 220 void writer_init_growingmemwriter(writer_t*w, U32 grow)
 221 {
 222     struct growmemwrite_t *mr;
 223     mr = (struct growmemwrite_t *)malloc(sizeof(struct growmemwrite_t));
 224     mr->length = 4096;
 225     mr->data = (unsigned char *)malloc(mr->length);
 226     mr->grow = grow;
 227     memset(w, 0, sizeof(writer_t));
 228     w->write = writer_growmemwrite_write;
 229     w->finish = writer_growmemwrite_finish;
 230     w->internal = (void*)mr;
 231     w->type = WRITER_TYPE_GROWING_MEM;
 232     w->bitpos = 0;
 233     w->mybyte = 0;
 234     w->pos = 0;
 235 }
 236
 237 /* ---------------------------- file writer ------------------------------- */
 238
 239 struct filewrite_t
 240 {
 241     int handle;
 242     char free_handle;
 243 };
 244
 245 static int writer_filewrite_write(writer_t*w, void* data, int len)
 246 {
 247     struct filewrite_t * fw= (struct filewrite_t*)w->internal;
 248     return write(fw->handle, data, len);
 249 }
 250 static void writer_filewrite_finish(writer_t*w)
 251 {
 252     struct filewrite_t *mr = (struct filewrite_t*)w->internal;
 253     if(mr->free_handle)
 254         close(mr->handle);
 255     free(w->internal);
 256     memset(w, 0, sizeof(writer_t));
 257 }
 258 void writer_init_filewriter(writer_t*w, int handle)
 259 {
 260     struct filewrite_t *mr = (struct filewrite_t *)malloc(sizeof(struct filewrite_t));
 261     mr->handle = handle;
 262     mr->free_handle = 0;
 263     memset(w, 0, sizeof(writer_t));
 264     w->write = writer_filewrite_write;
 265     w->finish = writer_filewrite_finish;
 266     w->internal = mr;
 267     w->type = WRITER_TYPE_FILE;
 268     w->bitpos = 0;
 269     w->mybyte = 0;
 270     w->pos = 0;
 271 }
 272 void writer_init_filewriter2(writer_t*w, char*filename)
 273 {
 274     int fi = open("movie.swf",
 275 #ifdef O_BINARY
 276             O_BINARY|
 277 #endif
 278             O_WRONLY|O_CREAT|O_TRUNC, 0644);
 279     writer_init_filewriter(w, fi);
 280     ((struct filewrite_t*)w->internal)->free_handle = 1;
 281 }
 282
 283 /* ---------------------------- null writer ------------------------------- */
 284
 285 static int writer_nullwrite_write(writer_t*w, void* data, int len)
 286 {
 287     w->pos += len;
 288     return len;
 289 }
 290 static void writer_nullwrite_finish(writer_t*w)
 291 {
 292     memset(w, 0, sizeof(writer_t));
 293 }
 294 void writer_init_nullwriter(writer_t*w)
 295 {
 296     memset(w, 0, sizeof(writer_t));
 297     w->write = writer_nullwrite_write;
 298     w->finish = writer_nullwrite_finish;
 299     w->internal = 0;
 300     w->type = WRITER_TYPE_NULL;
 301     w->bitpos = 0;
 302     w->mybyte = 0;
 303     w->pos = 0;
 304 }
 305 /* ---------------------------- zlibinflate reader -------------------------- */
 306
 307 struct zlibinflate_t
 308 {
 309 #ifdef HAVE_ZLIB
 310     z_stream zs;
 311     reader_t*input;
 312     unsigned char readbuffer[ZLIB_BUFFER_SIZE];
 313 #endif
 314 };
 315
 316 #ifdef HAVE_ZLIB
 317 static void zlib_error(int ret, char* msg, z_stream*zs)
 318 {
 319     fprintf(stderr, "%s: zlib error (%d): last zlib error: %s\n",
 320           msg,
 321           ret,
 322           zs->msg?zs->msg:"unknown");
 323     perror("errno:");
 324     exit(1);
 325 }
 326 #endif
 327
 328 static int reader_zlibinflate(reader_t*reader, void* data, int len)
 329 {
 330 #ifdef HAVE_ZLIB
 331     struct zlibinflate_t*z = (struct zlibinflate_t*)reader->internal;
 332     int ret;
 333     if(!z) {
 334         return 0;
 335     }
 336     if(!len)
 337         return 0;
 338
 339     z->zs.next_out = (Bytef *)data;
 340     z->zs.avail_out = len;
 341
 342     while(1) {
 343         if(!z->zs.avail_in) {
 344             z->zs.avail_in = z->input->read(z->input, z->readbuffer, ZLIB_BUFFER_SIZE);
 345             z->zs.next_in = z->readbuffer;
 346         }
 347         if(z->zs.avail_in)
 348             ret = inflate(&z->zs, Z_NO_FLUSH);
 349         else
 350             ret = inflate(&z->zs, Z_FINISH);
 351
 352         if (ret != Z_OK &&
 353             ret != Z_STREAM_END) zlib_error(ret, "bitio:inflate_inflate", &z->zs);
 354
 355         if (ret == Z_STREAM_END) {
 356                 int pos = z->zs.next_out - (Bytef*)data;
 357                 ret = inflateEnd(&z->zs);
 358                 if (ret != Z_OK) zlib_error(ret, "bitio:inflate_end", &z->zs);
 359                 free(reader->internal);
 360                 reader->internal = 0;
 361                 reader->pos += pos;
 362                 return pos;
 363         }
 364         if(!z->zs.avail_out) {
 365             break;
 366         }
 367     }
 368     reader->pos += len;
 369     return len;
 370 #else
 371     fprintf(stderr, "Error: swftools was compiled without zlib support");
 372     exit(1);
 373 #endif
 374 }
 375 static void reader_zlibinflate_dealloc(reader_t*reader)
 376 {
 377 #ifdef HAVE_ZLIB
 378     struct zlibinflate_t*z = (struct zlibinflate_t*)reader->internal;
 379     /* test whether read() already did basic deallocation */
 380     if(reader->internal) {
 381         inflateEnd(&z->zs);
 382         free(reader->internal);
 383     }
 384     memset(reader, 0, sizeof(reader_t));
 385 #endif
 386 }
 387 void reader_init_zlibinflate(reader_t*r, reader_t*input)
 388 {
 389 #ifdef HAVE_ZLIB
 390     struct zlibinflate_t*z;
 391     int ret;
 392     memset(r, 0, sizeof(reader_t));
 393     z = (struct zlibinflate_t*)malloc(sizeof(struct zlibinflate_t));
 394     memset(z, 0, sizeof(struct zlibinflate_t));
 395     r->internal = z;
 396     r->read = reader_zlibinflate;
 397     r->dealloc = reader_zlibinflate_dealloc;
 398     r->type = READER_TYPE_ZLIB;
 399     r->pos = 0;
 400     z->input = input;
 401     memset(&z->zs,0,sizeof(z_stream));
 402     z->zs.zalloc = Z_NULL;
 403     z->zs.zfree  = Z_NULL;
 404     z->zs.opaque = Z_NULL;
 405     ret = inflateInit(&z->zs);
 406     if (ret != Z_OK) zlib_error(ret, "bitio:inflate_init", &z->zs);
 407     reader_resetbits(r);
 408 #else
 409     fprintf(stderr, "Error: swftools was compiled without zlib support");
 410     exit(1);
 411 #endif
 412 }
 413
 414 /* ---------------------------- zlibdeflate writer -------------------------- */
 415
 416 struct zlibdeflate_t
 417 {
 418 #ifdef HAVE_ZLIB
 419     z_stream zs;
 420     writer_t*output;
 421     unsigned char writebuffer[ZLIB_BUFFER_SIZE];
 422 #endif
 423 };
 424
 425 static int writer_zlibdeflate_write(writer_t*writer, void* data, int len)
 426 {
 427 #ifdef HAVE_ZLIB
 428     struct zlibdeflate_t*z = (struct zlibdeflate_t*)writer->internal;
 429     int ret;
 430     if(writer->type != WRITER_TYPE_ZLIB) {
 431         fprintf(stderr, "Wrong writer ID (writer not initialized?)\n");
 432         return 0;
 433     }
 434     if(!z) {
 435         fprintf(stderr, "zlib not initialized!\n");
 436         return 0;
 437     }
 438     if(!len)
 439         return 0;
 440
 441     z->zs.next_in = (Bytef *)data;
 442     z->zs.avail_in = len;
 443
 444     while(1) {
 445         ret = deflate(&z->zs, Z_NO_FLUSH);
 446
 447         if (ret != Z_OK) zlib_error(ret, "bitio:deflate_deflate", &z->zs);
 448
 449         if(z->zs.next_out != z->writebuffer) {
 450             z->output->write(z->output, z->writebuffer, z->zs.next_out - (Bytef*)z->writebuffer);
 451             z->zs.next_out = z->writebuffer;
 452             z->zs.avail_out = ZLIB_BUFFER_SIZE;
 453         }
 454
 455         if(!z->zs.avail_in) {
 456             break;
 457         }
 458     }
 459     writer->pos += len;
 460     return len;
 461 #else
 462     fprintf(stderr, "Error: swftools was compiled without zlib support");
 463     exit(1);
 464 #endif
 465 }
 466 static void writer_zlibdeflate_finish(writer_t*writer)
 467 {
 468 #ifdef HAVE_ZLIB
 469     struct zlibdeflate_t*z = (struct zlibdeflate_t*)writer->internal;
 470     writer_t*output;
 471     int ret;
 472     if(writer->type != WRITER_TYPE_ZLIB) {
 473         fprintf(stderr, "Wrong writer ID (writer not initialized?)\n");
 474         return;
 475     }
 476     if(!z)
 477         return;
 478     output= z->output;
 479     while(1) {
 480         ret = deflate(&z->zs, Z_FINISH);
 481         if (ret != Z_OK &&
 482             ret != Z_STREAM_END) zlib_error(ret, "bitio:deflate_finish", &z->zs);
 483
 484         if(z->zs.next_out != z->writebuffer) {
 485             z->output->write(z->output, z->writebuffer, z->zs.next_out - (Bytef*)z->writebuffer);
 486             z->zs.next_out = z->writebuffer;
 487             z->zs.avail_out = ZLIB_BUFFER_SIZE;
 488         }
 489
 490         if (ret == Z_STREAM_END) {
 491             break;
 492
 493         }
 494     }
 495     ret = deflateEnd(&z->zs);
 496     if (ret != Z_OK) zlib_error(ret, "bitio:deflate_end", &z->zs);
 497     free(writer->internal);
 498     memset(writer, 0, sizeof(writer_t));
 499     //output->finish(output);
 500 #else
 501     fprintf(stderr, "Error: swftools was compiled without zlib support");
 502     exit(1);
 503 #endif
 504 }
 505 void writer_init_zlibdeflate(writer_t*w, writer_t*output)
 506 {
 507 #ifdef HAVE_ZLIB
 508     struct zlibdeflate_t*z;
 509     int ret;
 510     memset(w, 0, sizeof(writer_t));
 511     z = (struct zlibdeflate_t*)malloc(sizeof(struct zlibdeflate_t));
 512     memset(z, 0, sizeof(struct zlibdeflate_t));
 513     w->internal = z;
 514     w->write = writer_zlibdeflate_write;
 515     w->finish = writer_zlibdeflate_finish;
 516     w->type = WRITER_TYPE_ZLIB;
 517     w->pos = 0;
 518     z->output = output;
 519     memset(&z->zs,0,sizeof(z_stream));
 520     z->zs.zalloc = Z_NULL;
 521     z->zs.zfree  = Z_NULL;
 522     z->zs.opaque = Z_NULL;
 523     ret = deflateInit(&z->zs, 9);
 524     if (ret != Z_OK) zlib_error(ret, "bitio:deflate_init", &z->zs);
 525     w->bitpos = 0;
 526     w->mybyte = 0;
 527     z->zs.next_out = z->writebuffer;
 528     z->zs.avail_out = ZLIB_BUFFER_SIZE;
 529 #else
 530     fprintf(stderr, "Error: swftools was compiled without zlib support");
 531     exit(1);
 532 #endif
 533 }
 534
 535 /* ----------------------- bit handling routines -------------------------- */
 536
 537 void writer_writebit(writer_t*w, int bit)
 538 {
 539     if(w->bitpos==8)
 540     {
 541         w->write(w, &w->mybyte, 1);
 542         w->bitpos = 0;
 543         w->mybyte = 0;
 544     }
 545     if(bit&1)
 546         w->mybyte |= 1 << (7 - w->bitpos);
 547     w->bitpos ++;
 548 }
 549 void writer_writebits(writer_t*w, unsigned int data, int bits)
 550 {
 551     int t;
 552     for(t=0;t<bits;t++)
 553     {
 554         writer_writebit(w, (data >> (bits-t-1))&1);
 555     }
 556 }
 557 void writer_resetbits(writer_t*w)
 558 {
 559     if(w->bitpos)
 560         w->write(w, &w->mybyte, 1);
 561     w->bitpos = 0;
 562     w->mybyte = 0;
 563 }
 564
 565 unsigned int reader_readbit(reader_t*r)
 566 {
 567     if(r->bitpos==8)
 568     {
 569         r->bitpos=0;
 570         r->read(r, &r->mybyte, 1);
 571     }
 572     return (r->mybyte>>(7-r->bitpos++))&1;
 573 }
 574 unsigned int reader_readbits(reader_t*r, int num)
 575 {
 576     int t;
 577     int val = 0;
 578     for(t=0;t<num;t++)
 579     {
 580         val<<=1;
 581         val|=reader_readbit(r);
 582     }
 583     return val;
 584 }
 585 void reader_resetbits(reader_t*r)
 586 {
 587     r->mybyte = 0;
 588     r->bitpos = 8;
 589
 590 }
 591
 592 U8 reader_readU8(reader_t*r)
 593 {
 594     U8 b;
 595     r->read(r, &b, 1);
 596     return b;
 597 }
 598 U16 reader_readU16(reader_t*r)
 599 {
 600     U8 b1,b2;
 601     r->read(r, &b1, 1);
 602     r->read(r, &b2, 1);
 603     return b1|b2<<8;
 604 }
 605 U32 reader_readU32(reader_t*r)
 606 {
 607     U8 b1,b2,b3,b4;
 608     r->read(r, &b1, 1);
 609     r->read(r, &b2, 1);
 610     r->read(r, &b3, 1);
 611     r->read(r, &b4, 1);
 612     return b1|b2<<8|b3<<16|b4<<24;
 613 }
 614 float reader_readFloat(reader_t*r)
 615 {
 616     U8 b1,b2,b3,b4;
 617     r->read(r, &b1, 1);
 618     r->read(r, &b2, 1);
 619     r->read(r, &b3, 1);
 620     r->read(r, &b4, 1);
 621     U32 w = (b1|b2<<8|b3<<16|b4<<24);
 622     return *(float*)&w;
 623 }
 624 double reader_readDouble(reader_t*r)
 625 {
 626     double f;
 627     r->read(r, &f, 8);
 628     return f;
 629
 630     U8 b[8];
 631     r->read(r, b, 8);
 632     U64 w = ((U64)b[0]|(U64)b[1]<<8|(U64)b[2]<<16|(U64)b[3]<<24|(U64)b[4]<<32|(U64)b[5]<<40|(U64)b[6]<<48|(U64)b[7]<<56);
 633     return *(double*)&w;
 634 }
 635 char*reader_readString(reader_t*r)
 636 {
 637     writer_t g;
 638     writer_init_growingmemwriter(&g, 16);
 639     while(1) {
 640         U8 b = reader_readU8(r);
 641         writer_writeU8(&g, b);
 642         if(!b)
 643             break;
 644     }
 645     char*string = (char*)writer_growmemwrite_getmem(&g);
 646     writer_growmemwrite_finish(&g);
 647     return string;
 648 }
 649
 650 void writer_writeString(writer_t*w, const char*s)
 651 {
 652     int l = strlen(s);
 653     char zero = 0;
 654     w->write(w, (void*)s, l);
 655     w->write(w, &zero, 1);
 656 }
 657 void writer_writeU8(writer_t*w, unsigned char b)
 658 {
 659     w->write(w, &b, 1);
 660 }
 661 void writer_writeU16(writer_t*w, unsigned short v)
 662 {
 663     unsigned char b1 = v;
 664     unsigned char b2 = v>>8;
 665     w->write(w, &b1, 1);
 666     w->write(w, &b2, 1);
 667 }
 668 void writer_writeU32(writer_t*w, unsigned long v)
 669 {
 670     unsigned char b1 = v;
 671     unsigned char b2 = v>>8;
 672     unsigned char b3 = v>>16;
 673     unsigned char b4 = v>>24;
 674     w->write(w, &b1, 1);
 675     w->write(w, &b2, 1);
 676     w->write(w, &b3, 1);
 677     w->write(w, &b4, 1);
 678 }
 679 void writer_writeFloat(writer_t*w, float f)
 680 {
 681     unsigned long v = *(unsigned long*)&f;
 682     unsigned char b1 = v;
 683     unsigned char b2 = v>>8;
 684     unsigned char b3 = v>>16;
 685     unsigned char b4 = v>>24;
 686     w->write(w, &b1, 1);
 687     w->write(w, &b2, 1);
 688     w->write(w, &b3, 1);
 689     w->write(w, &b4, 1);
 690 }
 691 void writer_writeDouble(writer_t*w, double f)
 692 {
 693     w->write(w, &f, 8);
 694     return;
 695
 696     unsigned long long v = *(unsigned long long*)&f;
 697     unsigned char b1 = v;
 698     unsigned char b2 = v>>8;
 699     unsigned char b3 = v>>16;
 700     unsigned char b4 = v>>24;
 701     unsigned char b5 = v>>32;
 702     unsigned char b6 = v>>40;
 703     unsigned char b7 = v>>48;
 704     unsigned char b8 = v>>56;
 705     w->write(w, &b1, 1);
 706     w->write(w, &b2, 1);
 707     w->write(w, &b3, 1);
 708     w->write(w, &b4, 1);
 709     w->write(w, &b5, 1);
 710     w->write(w, &b6, 1);
 711     w->write(w, &b7, 1);
 712     w->write(w, &b8, 1);
 713 }