text: /*
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code 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
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  /* gzlib.c -- zlib functions common to reading and writing gzip files
   * Copyright (C) 2004-2017 Mark Adler
   * For conditions of distribution and use, see copyright notice in zlib.h
   */
  
  #include "gzguts.h"
  
  #if defined(_WIN32) && !defined(__BORLANDC__) && !defined(__MINGW32__)
  #  define LSEEK _lseeki64
  #else
  #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
  #  define LSEEK lseek64
  #else
  #  define LSEEK lseek
  #endif
  #endif
  
  /* Local functions */
  local void gz_reset OF((gz_statep));
  local gzFile gz_open OF((const void *, int, const char *));
  
  #if defined UNDER_CE
  
  /* Map the Windows error number in ERROR to a locale-dependent error message
     string and return a pointer to it.  Typically, the values for ERROR come
     from GetLastError.
  
     The string pointed to shall not be modified by the application, but may be
     overwritten by a subsequent call to gz_strwinerror
  
     The gz_strwinerror function does not change the current setting of
     GetLastError. */
  char ZLIB_INTERNAL *gz_strwinerror (error)
       DWORD error;
  {
      static char buf[1024];
  
      wchar_t *msgbuf;
      DWORD lasterr = GetLastError();
      DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
          | FORMAT_MESSAGE_ALLOCATE_BUFFER,
          NULL,
          error,
          0, /* Default language */
          (LPVOID)&msgbuf,
          0,
          NULL);
      if (chars != 0) {
          /* If there is an \r\n appended, zap it.  */
          if (chars >= 2
              && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
              chars -= 2;
              msgbuf[chars] = 0;
          }
  
          if (chars > sizeof (buf) - 1) {
              chars = sizeof (buf) - 1;
              msgbuf[chars] = 0;
          }
  
          wcstombs(buf, msgbuf, chars + 1);
          LocalFree(msgbuf);
      }
      else {
          sprintf(buf, "unknown win32 error (%ld)", error);
      }
  
      SetLastError(lasterr);
      return buf;
  }
  
  #endif /* UNDER_CE */
  
  /* Reset gzip file state */
  local void gz_reset(state)
      gz_statep state;
  {
      state->x.have = 0;              /* no output data available */
      if (state->mode == GZ_READ) {   /* for reading ... */
          state->eof = 0;             /* not at end of file */
          state->past = 0;            /* have not read past end yet */
          state->how = LOOK;          /* look for gzip header */
      }
      state->seek = 0;                /* no seek request pending */
      gz_error(state, Z_OK, NULL);    /* clear error */
      state->x.pos = 0;               /* no uncompressed data yet */
      state->strm.avail_in = 0;       /* no input data yet */
  }
  
  /* Open a gzip file either by name or file descriptor. */
  local gzFile gz_open(path, fd, mode)
      const void *path;
      int fd;
      const char *mode;
  {
      gz_statep state;
      z_size_t len;
      int oflag;
  #ifdef O_CLOEXEC
      int cloexec = 0;
  #endif
  #ifdef O_EXCL
      int exclusive = 0;
  #endif
  
      /* check input */
      if (path == NULL)
          return NULL;
  
      /* allocate gzFile structure to return */
      state = (gz_statep)malloc(sizeof(gz_state));
      if (state == NULL)
          return NULL;
      state->size = 0;            /* no buffers allocated yet */
      state->want = GZBUFSIZE;    /* requested buffer size */
      state->msg = NULL;          /* no error message yet */
  
      /* interpret mode */
      state->mode = GZ_NONE;
      state->level = Z_DEFAULT_COMPRESSION;
      state->strategy = Z_DEFAULT_STRATEGY;
      state->direct = 0;
      while (*mode) {
          if (*mode >= '0' && *mode <= '9')
              state->level = *mode - '0';
          else
              switch (*mode) {
              case 'r':
                  state->mode = GZ_READ;
                  break;
  #ifndef NO_GZCOMPRESS
              case 'w':
                  state->mode = GZ_WRITE;
                  break;
              case 'a':
                  state->mode = GZ_APPEND;
                  break;
  #endif
              case '+':       /* can't read and write at the same time */
                  free(state);
                  return NULL;
              case 'b':       /* ignore -- will request binary anyway */
                  break;
  #ifdef O_CLOEXEC
              case 'e':
                  cloexec = 1;
                  break;
  #endif
  #ifdef O_EXCL
              case 'x':
                  exclusive = 1;
                  break;
  #endif
              case 'f':
                  state->strategy = Z_FILTERED;
                  break;
              case 'h':
                  state->strategy = Z_HUFFMAN_ONLY;
                  break;
              case 'R':
                  state->strategy = Z_RLE;
                  break;
              case 'F':
                  state->strategy = Z_FIXED;
                  break;
              case 'T':
                  state->direct = 1;
                  break;
              default:        /* could consider as an error, but just ignore */
                  ;
              }
          mode++;
      }
  
      /* must provide an "r", "w", or "a" */
      if (state->mode == GZ_NONE) {
          free(state);
          return NULL;
      }
  
      /* can't force transparent read */
      if (state->mode == GZ_READ) {
          if (state->direct) {
              free(state);
              return NULL;
          }
          state->direct = 1;      /* for empty file */
      }
  
      /* save the path name for error messages */
  #ifdef WIDECHAR
      if (fd == -2) {
          len = wcstombs(NULL, path, 0);
          if (len == (z_size_t)-1)
              len = 0;
      }
      else
  #endif
          len = strlen((const char *)path);
      state->path = (char *)malloc(len + 1);
      if (state->path == NULL) {
          free(state);
          return NULL;
      }
  #ifdef WIDECHAR
      if (fd == -2)
          if (len)
              wcstombs(state->path, path, len + 1);
          else
              *(state->path) = 0;
      else
  #endif
  #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
          (void)snprintf(state->path, len + 1, "%s", (const char *)path);
  #else
          strcpy(state->path, path);
  #endif
  
      /* compute the flags for open() */
      oflag =
  #ifdef O_LARGEFILE
          O_LARGEFILE |
  #endif
  #ifdef O_BINARY
          O_BINARY |
  #endif
  #ifdef O_CLOEXEC
          (cloexec ? O_CLOEXEC : 0) |
  #endif
          (state->mode == GZ_READ ?
           O_RDONLY :
           (O_WRONLY | O_CREAT |
  #ifdef O_EXCL
            (exclusive ? O_EXCL : 0) |
  #endif
            (state->mode == GZ_WRITE ?
             O_TRUNC :
             O_APPEND)));
  
      /* open the file with the appropriate flags (or just use fd) */
      state->fd = fd > -1 ? fd : (
  #ifdef WIDECHAR
          fd == -2 ? _wopen(path, oflag, 0666) :
  #endif
          open((const char *)path, oflag, 0666));
      if (state->fd == -1) {
          free(state->path);
          free(state);
          return NULL;
      }
      if (state->mode == GZ_APPEND) {
          LSEEK(state->fd, 0, SEEK_END);  /* so gzoffset() is correct */
          state->mode = GZ_WRITE;         /* simplify later checks */
      }
  
      /* save the current position for rewinding (only if reading) */
      if (state->mode == GZ_READ) {
          state->start = LSEEK(state->fd, 0, SEEK_CUR);
          if (state->start == -1) state->start = 0;
      }
  
      /* initialize stream */
      gz_reset(state);
  
      /* return stream */
      return (gzFile)state;
  }
  
  /* -- see zlib.h -- */
  gzFile ZEXPORT gzopen(path, mode)
      const char *path;
      const char *mode;
  {
      return gz_open(path, -1, mode);
  }
  
  /* -- see zlib.h -- */
  gzFile ZEXPORT gzopen64(path, mode)
      const char *path;
      const char *mode;
  {
      return gz_open(path, -1, mode);
  }
  
  /* -- see zlib.h -- */
  gzFile ZEXPORT gzdopen(fd, mode)
      int fd;
      const char *mode;
  {
      char *path;         /* identifier for error messages */
      gzFile gz;
  
      if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
          return NULL;
  #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
      (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd);
  #else
      sprintf(path, "<fd:%d>", fd);   /* for debugging */
  #endif
      gz = gz_open(path, fd, mode);
      free(path);
      return gz;
  }
  
  /* -- see zlib.h -- */
  #ifdef WIDECHAR
  gzFile ZEXPORT gzopen_w(path, mode)
      const wchar_t *path;
      const char *mode;
  {
      return gz_open(path, -2, mode);
  }
  #endif
  
  /* -- see zlib.h -- */
  int ZEXPORT gzbuffer(file, size)
      gzFile file;
      unsigned size;
  {
      gz_statep state;
  
      /* get internal structure and check integrity */
      if (file == NULL)
          return -1;
      state = (gz_statep)file;
      if (state->mode != GZ_READ && state->mode != GZ_WRITE)
          return -1;
  
      /* make sure we haven't already allocated memory */
      if (state->size != 0)
          return -1;
  
      /* check and set requested size */
      if ((size << 1) < size)
          return -1;              /* need to be able to double it */
      if (size < 2)
          size = 2;               /* need two bytes to check magic header */
      state->want = size;
      return 0;
  }
  
  /* -- see zlib.h -- */
  int ZEXPORT gzrewind(file)
      gzFile file;
  {
      gz_statep state;
  
      /* get internal structure */
      if (file == NULL)
          return -1;
      state = (gz_statep)file;
  
      /* check that we're reading and that there's no error */
      if (state->mode != GZ_READ ||
              (state->err != Z_OK && state->err != Z_BUF_ERROR))
          return -1;
  
      /* back up and start over */
      if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
          return -1;
      gz_reset(state);
      return 0;
  }
  
  /* -- see zlib.h -- */
  z_off64_t ZEXPORT gzseek64(file, offset, whence)
      gzFile file;
      z_off64_t offset;
      int whence;
  {
      unsigned n;
      z_off64_t ret;
      gz_statep state;
  
      /* get internal structure and check integrity */
      if (file == NULL)
          return -1;
      state = (gz_statep)file;
      if (state->mode != GZ_READ && state->mode != GZ_WRITE)
          return -1;
  
      /* check that there's no error */
      if (state->err != Z_OK && state->err != Z_BUF_ERROR)
          return -1;
  
      /* can only seek from start or relative to current position */
      if (whence != SEEK_SET && whence != SEEK_CUR)
          return -1;
  
      /* normalize offset to a SEEK_CUR specification */
      if (whence == SEEK_SET)
          offset -= state->x.pos;
      else if (state->seek)
          offset += state->skip;
      state->seek = 0;
  
      /* if within raw area while reading, just go there */
      if (state->mode == GZ_READ && state->how == COPY &&
              state->x.pos + offset >= 0) {
          ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
          if (ret == -1)
              return -1;
          state->x.have = 0;
          state->eof = 0;
          state->past = 0;
          state->seek = 0;
          gz_error(state, Z_OK, NULL);
          state->strm.avail_in = 0;
          state->x.pos += offset;
          return state->x.pos;
      }
  
      /* calculate skip amount, rewinding if needed for back seek when reading */
      if (offset < 0) {
          if (state->mode != GZ_READ)         /* writing -- can't go backwards */
              return -1;
          offset += state->x.pos;
          if (offset < 0)                     /* before start of file! */
              return -1;
          if (gzrewind(file) == -1)           /* rewind, then skip to offset */
              return -1;
      }
  
      /* if reading, skip what's in output buffer (one less gzgetc() check) */
      if (state->mode == GZ_READ) {
          n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ?
              (unsigned)offset : state->x.have;
          state->x.have -= n;
          state->x.next += n;
          state->x.pos += n;
          offset -= n;
      }
  
      /* request skip (if not zero) */
      if (offset) {
          state->seek = 1;
          state->skip = offset;
      }
      return state->x.pos + offset;
  }
  
  /* -- see zlib.h -- */
  z_off_t ZEXPORT gzseek(file, offset, whence)
      gzFile file;
      z_off_t offset;
      int whence;
  {
      z_off64_t ret;
  
      ret = gzseek64(file, (z_off64_t)offset, whence);
      return ret == (z_off_t)ret ? (z_off_t)ret : -1;
  }
  
  /* -- see zlib.h -- */
  z_off64_t ZEXPORT gztell64(file)
      gzFile file;
  {
      gz_statep state;
  
      /* get internal structure and check integrity */
      if (file == NULL)
          return -1;
      state = (gz_statep)file;
      if (state->mode != GZ_READ && state->mode != GZ_WRITE)
          return -1;
  
      /* return position */
      return state->x.pos + (state->seek ? state->skip : 0);
  }
  
  /* -- see zlib.h -- */
  z_off_t ZEXPORT gztell(file)
      gzFile file;
  {
      z_off64_t ret;
  
      ret = gztell64(file);
      return ret == (z_off_t)ret ? (z_off_t)ret : -1;
  }
  
  /* -- see zlib.h -- */
  z_off64_t ZEXPORT gzoffset64(file)
      gzFile file;
  {
      z_off64_t offset;
      gz_statep state;
  
      /* get internal structure and check integrity */
      if (file == NULL)
          return -1;
      state = (gz_statep)file;
      if (state->mode != GZ_READ && state->mode != GZ_WRITE)
          return -1;
  
      /* compute and return effective offset in file */
      offset = LSEEK(state->fd, 0, SEEK_CUR);
      if (offset == -1)
          return -1;
      if (state->mode == GZ_READ)             /* reading */
          offset -= state->strm.avail_in;     /* don't count buffered input */
      return offset;
  }
  
  /* -- see zlib.h -- */
  z_off_t ZEXPORT gzoffset(file)
      gzFile file;
  {
      z_off64_t ret;
  
      ret = gzoffset64(file);
      return ret == (z_off_t)ret ? (z_off_t)ret : -1;
  }
  
  /* -- see zlib.h -- */
  int ZEXPORT gzeof(file)
      gzFile file;
  {
      gz_statep state;
  
      /* get internal structure and check integrity */
      if (file == NULL)
          return 0;
      state = (gz_statep)file;
      if (state->mode != GZ_READ && state->mode != GZ_WRITE)
          return 0;
  
      /* return end-of-file state */
      return state->mode == GZ_READ ? state->past : 0;
  }
  
  /* -- see zlib.h -- */
  const char * ZEXPORT gzerror(file, errnum)
      gzFile file;
      int *errnum;
  {
      gz_statep state;
  
      /* get internal structure and check integrity */
      if (file == NULL)
          return NULL;
      state = (gz_statep)file;
      if (state->mode != GZ_READ && state->mode != GZ_WRITE)
          return NULL;
  
      /* return error information */
      if (errnum != NULL)
          *errnum = state->err;
      return state->err == Z_MEM_ERROR ? "out of memory" :
                                         (state->msg == NULL ? "" : state->msg);
  }
  
  /* -- see zlib.h -- */
  void ZEXPORT gzclearerr(file)
      gzFile file;
  {
      gz_statep state;
  
      /* get internal structure and check integrity */
      if (file == NULL)
          return;
      state = (gz_statep)file;
      if (state->mode != GZ_READ && state->mode != GZ_WRITE)
          return;
  
      /* clear error and end-of-file */
      if (state->mode == GZ_READ) {
          state->eof = 0;
          state->past = 0;
      }
      gz_error(state, Z_OK, NULL);
  }
  
  /* Create an error message in allocated memory and set state->err and
     state->msg accordingly.  Free any previous error message already there.  Do
     not try to free or allocate space if the error is Z_MEM_ERROR (out of
     memory).  Simply save the error message as a static string.  If there is an
     allocation failure constructing the error message, then convert the error to
     out of memory. */
  void ZLIB_INTERNAL gz_error(state, err, msg)
      gz_statep state;
      int err;
      const char *msg;
  {
      /* free previously allocated message and clear */
      if (state->msg != NULL) {
          if (state->err != Z_MEM_ERROR)
              free(state->msg);
          state->msg = NULL;
      }
  
      /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
      if (err != Z_OK && err != Z_BUF_ERROR)
          state->x.have = 0;
  
      /* set error code, and if no message, then done */
      state->err = err;
      if (msg == NULL)
          return;
  
      /* for an out of memory error, return literal string when requested */
      if (err == Z_MEM_ERROR)
          return;
  
      /* construct error message with path */
      if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
              NULL) {
          state->err = Z_MEM_ERROR;
          return;
      }
  #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
      (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
                     "%s%s%s", state->path, ": ", msg);
  #else
      strcpy(state->msg, state->path);
      strcat(state->msg, ": ");
      strcat(state->msg, msg);
  #endif
  }
  
  #ifndef INT_MAX
  /* portably return maximum value for an int (when limits.h presumed not
     available) -- we need to do this to cover cases where 2's complement not
     used, since C standard permits 1's complement and sign-bit representations,
     otherwise we could just use ((unsigned)-1) >> 1 */
  unsigned ZLIB_INTERNAL gz_intmax()
  {
      unsigned p, q;
  
      p = 1;
      do {
          q = p;
          p <<= 1;
          p++;
      } while (p > q);
      return q >> 1;
  }
  #endif
  