beos.c

给出了 zip 压缩算法的完整实现过程。

/*
  Copyright (c) 1990-2005 Info-ZIP.  All rights reserved.

  See the accompanying file LICENSE, version 2004-May-22 or later
  (the contents of which are also included in zip.h) for terms of use.
  If, for some reason, all these files are missing, the Info-ZIP license
  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
*/
/*

 This BeOS-specific file is based on unix.c in the unix directory; changes
 by Chris Herborth ([e-mail]).

*/

#include "zip.h"

#ifndef UTIL    /* the companion #endif is a bit of ways down ... */

#include <time.h>
#include <dirent.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include <dirent.h>

#include <kernel/fs_attr.h>
#include <storage/Mime.h>
#include <support/byteorder.h>


#define PAD 0
#define PATH_END '/'

/* Library functions not in (most) header files */

#ifdef _POSIX_VERSION
#  include <utime.h>
#else
   int utime OF((char *, time_t *));
#endif

extern char *label;
local ulg label_time = 0;
local ulg label_mode = 0;
local time_t label_utim = 0;

/* Local functions */
local char *readd OF((DIR *));
local int get_attr_dir( const char *, char **, off_t * );
local int add_UT_ef( struct zlist far * );
local int add_Ux_ef( struct zlist far * );
local int add_Be_ef( struct zlist far * );


#ifdef NO_DIR                    /* for AT&T 3B1 */
#include <sys/dir.h>
#ifndef dirent
#  define dirent direct
#endif
typedef FILE DIR;
/*
**  Apparently originally by Rich Salz.
**  Cleaned up and modified by James W. Birdsall.
*/

#define opendir(path) fopen(path, "r")

struct dirent *readdir(dirp)
DIR *dirp;
{
  static struct dirent entry;

  if (dirp == NULL)
    return NULL;
  for (;;)
    if (fread (&entry, sizeof (struct dirent), 1, dirp) == 0)
      return NULL;
    else if (entry.d_ino)
      return (&entry);
} /* end of readdir() */

#define closedir(dirp) fclose(dirp)
#endif /* NO_DIR */


local char *readd(d)
DIR *d;                 /* directory stream to read from */
/* Return a pointer to the next name in the directory stream d, or NULL if
   no more entries or an error occurs. */
{
  struct dirent *e;

  e = readdir(d);
  return e == NULL ? (char *) NULL : e->d_name;
}

int procname(n, caseflag)
char *n;                /* name to process */
int caseflag;           /* true to force case-sensitive match */
/* Process a name or sh expression to operate on (or exclude).  Return
   an error code in the ZE_ class. */
{
  char *a;              /* path and name for recursion */
  DIR *d;               /* directory stream from opendir() */
  char *e;              /* pointer to name from readd() */
  int m;                /* matched flag */
  char *p;              /* path for recursion */
  struct stat s;        /* result of stat() */
  struct zlist far *z;  /* steps through zfiles list */

  if (strcmp(n, "-") == 0)   /* if compressing stdin */
    return newname(n, 0, caseflag);
  else if (LSSTAT(n, &s))
  {
    /* Not a file or directory--search for shell expression in zip file */
    p = ex2in(n, 0, (int *)NULL);       /* shouldn't affect matching chars */
    m = 1;
    for (z = zfiles; z != NULL; z = z->nxt) {
      if (MATCH(p, z->iname, caseflag))
      {
        z->mark = pcount ? filter(z->zname, caseflag) : 1;
        if (verbose)
            fprintf(mesg, "zip diagnostic: %scluding %s\n",
               z->mark ? "in" : "ex", z->name);
        m = 0;
      }
    }
    free((zvoid *)p);
    return m ? ZE_MISS : ZE_OK;
  }

  /* Live name--use if file, recurse if directory */
  if ((s.st_mode & S_IFDIR) == 0)
  {
    /* add or remove name of file */
    if ((m = newname(n, 0, caseflag)) != ZE_OK)
      return m;
  } else {
    /* Add trailing / to the directory name */
    if ((p = malloc(strlen(n)+2)) == NULL)
      return ZE_MEM;
    if (strcmp(n, ".") == 0) {
      *p = '\0';  /* avoid "./" prefix and do not create zip entry */
    } else {
      strcpy(p, n);
      a = p + strlen(p);
      if (a[-1] != '/')
        strcpy(a, "/");
      if (dirnames && (m = newname(p, 1, caseflag)) != ZE_OK) {
        free((zvoid *)p);
        return m;
      }
    }
    /* recurse into directory */
    if (recurse && (d = opendir(n)) != NULL)
    {
      while ((e = readd(d)) != NULL) {
        if (strcmp(e, ".") && strcmp(e, ".."))
        {
          if ((a = malloc(strlen(p) + strlen(e) + 1)) == NULL)
          {
            closedir(d);
            free((zvoid *)p);
            return ZE_MEM;
          }
          strcat(strcpy(a, p), e);
          if ((m = procname(a, caseflag)) != ZE_OK)   /* recurse on name */
          {
            if (m == ZE_MISS)
              zipwarn("name not matched: ", a);
            else
              ziperr(m, a);
          }
          free((zvoid *)a);
        }
      }
      closedir(d);
    }
    free((zvoid *)p);
  } /* (s.st_mode & S_IFDIR) == 0) */
  return ZE_OK;
}

char *ex2in(x, isdir, pdosflag)
char *x;                /* external file name */
int isdir;              /* input: x is a directory */
int *pdosflag;          /* output: force MSDOS file attributes? */
/* Convert the external file name to a zip file name, returning the malloc'ed
   string or NULL if not enough memory. */
{
  char *n;              /* internal file name (malloc'ed) */
  char *t;              /* shortened name */
  int dosflag;

  dosflag = dosify;  /* default for non-DOS and non-OS/2 */

  /* Find starting point in name before doing malloc */
  for (t = x; *t == '/'; t++)
    ;                   /* strip leading '/' chars to get a relative path */
  while (*t == '.' && t[1] == '/')
    t += 2;             /* strip redundant leading "./" sections */

  /* Make changes, if any, to the copied name (leave original intact) */
  if (!pathput)
    t = last(t, PATH_END);

  /* Malloc space for internal name and copy it */
  if ((n = malloc(strlen(t) + 1)) == NULL)
    return NULL;
  strcpy(n, t);

  if (isdir == 42) return n;    /* avoid warning on unused variable */

  if (dosify)
    msname(n);

  /* Returned malloc'ed name */
  if (pdosflag)
    *pdosflag = dosflag;
  return n;
}


char *in2ex(n)
char *n;                /* internal file name */
/* Convert the zip file name to an external file name, returning the malloc'ed
   string or NULL if not enough memory. */
{
  char *x;              /* external file name */

  if ((x = malloc(strlen(n) + 1 + PAD)) == NULL)
    return NULL;
  strcpy(x, n);
  return x;
}

/*
 * XXX use ztimbuf in both POSIX and non POSIX cases ?
 */
void stamp(f, d)
char *f;                /* name of file to change */
ulg d;                  /* dos-style time to change it to */
/* Set last updated and accessed time of file f to the DOS time d. */
{
#ifdef _POSIX_VERSION
  struct utimbuf u;     /* argument for utime()  const ?? */
#else
  time_t u[2];          /* argument for utime() */
#endif

  /* Convert DOS time to time_t format in u */
#ifdef _POSIX_VERSION
  u.actime = u.modtime = dos2unixtime(d);
  utime(f, &u);
#else
  u[0] = u[1] = dos2unixtime(d);
  utime(f, u);
#endif

}

ulg filetime(f, a, n, t)
char *f;                /* name of file to get info on */
ulg *a;                 /* return value: file attributes */
long *n;                /* return value: file size */
iztimes *t;             /* return value: access, modific. and creation times */
/* If file *f does not exist, return 0.  Else, return the file's last
   modified date and time as an MSDOS date and time.  The date and
   time is returned in a long with the date most significant to allow
   unsigned integer comparison of absolute times.  Also, if a is not
   a NULL pointer, store the file attributes there, with the high two
   bytes being the Unix attributes, and the low byte being a mapping
   of that to DOS attributes.  If n is not NULL, store the file size
   there.  If t is not NULL, the file's access, modification and creation
   times are stored there as UNIX time_t values.
   If f is "-", use standard input as the file. If f is a device, return
   a file size of -1 */
{
  struct stat s;        /* results of stat() */
  char *name;
  unsigned int len = strlen(f);

  if (f == label) {
    if (a != NULL)
      *a = label_mode;
    if (n != NULL)
      *n = -2L; /* convention for a label name */
    if (t != NULL)
      t->atime = t->mtime = t->ctime = label_utim;
    return label_time;
  }

  if ((name = malloc(len + 1)) == NULL) {
    ZIPERR(ZE_MEM, "filetime");
  }
  strcpy(name, f);
  if (name[len - 1] == '/')
    name[len - 1] = '\0';
  /* not all systems allow stat'ing a file with / appended */
  if (strcmp(f, "-") == 0) {
    if (fstat(fileno(stdin), &s) != 0) {
      free(name);
      error("fstat(stdin)");
    }
  } else if (LSSTAT(name, &s) != 0) {
             /* Accept about any file kind including directories
              * (stored with trailing / with -r option)
              */
    free(name);
    return 0;
  }

  if (a != NULL) {
    *a = ((ulg)s.st_mode << 16) | !(s.st_mode & S_IWRITE);
    if ((s.st_mode & S_IFMT) == S_IFDIR) {
      *a |= MSDOS_DIR_ATTR;
    }
  }
  if (n != NULL)
    *n = (s.st_mode & S_IFMT) == S_IFREG ? s.st_size : -1L;
  if (t != NULL) {
    t->atime = s.st_atime;
    t->mtime = s.st_mtime;
    t->ctime = s.st_mtime;   /* best guess (s.st_ctime: last status change!) */
  }

  free(name);

  return unix2dostime(&s.st_mtime);
}

/* ----------------------------------------------------------------------

Return a malloc()'d buffer containing all of the attributes and their names
for the file specified in name.  You have to free() this yourself.  The length
of the buffer is also returned.

If get_attr_dir() fails, the buffer will be NULL, total_size will be 0,
and an error will be returned:

    EOK    - no errors occurred
    EINVAL - attr_buff was pointing at a buffer
    ENOMEM - insufficient memory for attribute buffer

Other errors are possible (whatever is returned by the fs_attr.h functions).

PROBLEMS:

- pointers are 32-bits; attributes are limited to off_t in size so it's
  possible to overflow... in practice, this isn't too likely... your
  machine will thrash like hell before that happens

*/

#define INITIAL_BUFF_SIZE 65536

int get_attr_dir( const char *name, char **attr_buff, off_t *total_size )
{
    int               retval = EOK;
    int               fd;
    DIR              *fa_dir;
    struct dirent    *fa_ent;
    off_t             attrs_size;
    off_t             this_size;
    char             *ptr;
    struct attr_info  fa_info;
    struct attr_info  big_fa_info;

    retval      = EOK;
    attrs_size  = 0;    /* gcc still says this is used uninitialized... */
    *total_size = 0;

    /* ----------------------------------------------------------------- */
    /* Sanity-check.                                                     */
    if( *attr_buff != NULL ) {
        return EINVAL;
    }

    /* ----------------------------------------------------------------- */
    /* Can we open the file/directory?                                   */
    /*                                                                   */
    /* linkput is a zip global; it's set to 1 if we're storing symbolic  */
    /* links as symbolic links (instead of storing the thing the link    */
    /* points to)... if we're storing the symbolic link as a link, we'll */
    /* want the link's file attributes, otherwise we want the target's.  */
    if( linkput ) {
        fd = open( name, O_RDONLY | O_NOTRAVERSE );
    } else {
        fd = open( name, O_RDONLY );
    }
    if( fd < 0 ) {
        return errno;
    }

    /* ----------------------------------------------------------------- */
    /* Allocate an initial buffer; 64k should usually be enough.         */
    *attr_buff = (char *)malloc( INITIAL_BUFF_SIZE );
    ptr        = *attr_buff;
    if( ptr == NULL ) {
        close( fd );

        return ENOMEM;
    }

    /* ----------------------------------------------------------------- */
    /* Open the attributes directory for this file.                      */
    fa_dir = fs_fopen_attr_dir( fd );
    if( fa_dir == NULL ) {
        close( fd );

        free( ptr );
        *attr_buff = NULL;

        return retval;
    }

    /* ----------------------------------------------------------------- */
    /* Read all the attributes; the buffer could grow > 64K if there are */
    /* many and/or they are large.                                       */
    fa_ent = fs_read_attr_dir( fa_dir );
    while( fa_ent != NULL ) {
        retval = fs_stat_attr( fd, fa_ent->d_name, &fa_info );
        /* TODO: check retval != EOK */

        this_size  = strlen( fa_ent->d_name ) + 1;
        this_size += sizeof( struct attr_info );
        this_size += fa_info.size;

        attrs_size += this_size;

        if( attrs_size > INITIAL_BUFF_SIZE ) {
            unsigned long offset = ptr - *attr_buff;

            *attr_buff = (char *)realloc( *attr_buff, attrs_size );
            if( *attr_buff == NULL ) {
                retval = fs_close_attr_dir( fa_dir );
                /* TODO: check retval != EOK */
                close( fd );

                return ENOMEM;
            }

            ptr = *attr_buff + offset;
        }

        /* Now copy the data for this attribute into the buffer. */
        strcpy( ptr, fa_ent->d_name );
        ptr += strlen( fa_ent->d_name );
        *ptr++ = '\0';

        /* We need to put a big-endian version of the fa_info data into */
        /* the archive.                                                 */
        big_fa_info.type = B_HOST_TO_BENDIAN_INT32( fa_info.type );
        big_fa_info.size = B_HOST_TO_BENDIAN_INT64( fa_info.size );
        memcpy( ptr, &big_fa_info, sizeof( struct attr_info ) );
        ptr += sizeof( struct attr_info );

        if( fa_info.size > 0 ) {
            ssize_t read_bytes;

            read_bytes = fs_read_attr( fd, fa_ent->d_name, fa_info.type, 0,
                                       ptr, fa_info.size );
            if( read_bytes != fa_info.size ) {
                /* print a warning about mismatched sizes */
                char buff[80];

                sprintf( buff, "read %ld, expected %ld",
                         (ssize_t)read_bytes, (ssize_t)fa_info.size );