hash.c File Reference

#include <sys/param.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "../include/db.h"
#include "hash.h"
#include "page.h"
#include "extern.h"

Include dependency graph for hash.c:

Go to the source code of this file.

Macros
#define	ABNORMAL   (1)
#define	ERROR   (-1)
#define	MOD(x, y)   ((x) & ((y) - 1))
#define	OLDHASHVERSION   1
#define	RETURN_ERROR(ERR, LOC)   { save_errno = ERR; goto LOC; }
#define	SUCCESS   (0)

Functions
u_int32_t	__call_hash (HTAB *hashp, char *k, int len)
int	__expand_table (HTAB *hashp)
DB *	__hash_open (char *file, int flags, int mode, const HASHINFO *info, int dflags) const
static int alloc_segs	__P ((HTAB *, int))
static int flush_meta	__P ((HTAB *))
static int hash_access	__P ((HTAB *, ACTION, DBT *, DBT *))
static int hash_close	__P ((DB *))
static int hash_delete	__P ((const DB *, const DBT *, u_int32_t))
static int hash_fd	__P ((const DB *))
static int hash_get	__P ((const DB *, const DBT *, DBT *, u_int32_t))
static void *hash_realloc	__P ((SEGMENT **, int, int))
static int hash_seq	__P ((const DB *, DBT *, DBT *, u_int32_t))
static int hash_sync	__P ((const DB *, u_int32_t))
static HTAB *init_hash	__P ((HTAB *, const char *, const HASHINFO *))
static void swap_header_copy	__P ((HASHHDR *, HASHHDR *))
static int	alloc_segs (HTAB *hashp, int nsegs)
static int	flush_meta (HTAB *hashp)
static int	hash_access (HTAB *hashp, ACTION action, DBT *key, DBT *val)
static int	hash_close (DB *dbp)
static int	hash_delete (DB *dbp, const DBT *key, u_int32_t flag) const
static int	hash_fd (DB *dbp) const
static int	hash_get (DB *dbp, const DBT *key, DBT *data, u_int32_t flag) const
static int	hash_put (DB *dbp, DBT *key, const DBT *data, u_int32_t flag) const
static void *	hash_realloc (SEGMENT **p_ptr, int oldsize, int newsize)
static int	hash_seq (DB *dbp, DBT *key, DBT *data, u_int32_t flag) const
static int	hash_sync (DB *dbp, u_int32_t flags) const
static int	hdestroy (HTAB *hashp)
static HTAB *	init_hash (HTAB *hashp, const char *file, const HASHINFO *info)
static int	init_htab (HTAB *hashp, int nelem)
static void	swap_header (HTAB *hashp)
static void	swap_header_copy (HASHHDR *srcp, HASHHDR *destp)

Macro Definition Documentation

ABNORMAL

#define ABNORMAL   (1)

Definition at line 86 of file hash.c.

Referenced by hash_access(), and hash_seq().

ERROR

#define ERROR   (-1)

Definition at line 85 of file hash.c.

Referenced by hash_access(), hash_close(), hash_delete(), hash_fd(), hash_get(), hash_put(), hash_seq(), hash_sync(), hdestroy(), and vm_allocate_dh().

MOD

#define MOD	(		x,
			y
	)		((x) & ((y) - 1))

Definition at line 79 of file hash.c.

OLDHASHVERSION

#define OLDHASHVERSION   1

Referenced by __hash_open().

RETURN_ERROR

#define RETURN_ERROR	(		ERR,
			LOC
	)		{ save_errno = ERR; goto LOC; }

Definition at line 81 of file hash.c.

Referenced by __hash_open().

SUCCESS

#define SUCCESS   (0)

Definition at line 84 of file hash.c.

Referenced by hash_access(), hash_seq(), and hdestroy().

Function Documentation

__call_hash()

u_int32_t __call_hash	(	HTAB *	hashp,
		char *	k,
		int	len
	)

Definition at line 886 of file hash.c.

Referenced by __big_split(), __split_page(), hash_access(), and ugly_split().

{
   int n, bucket;

   n = hashp->hash(k, len);
   bucket = n & hashp->HIGH_MASK;
   if (bucket > hashp->MAX_BUCKET)
      bucket = bucket & hashp->LOW_MASK;
   return (bucket);
}

__expand_table()

int __expand_table

(

HTAB *

hashp

)

Definition at line 815 of file hash.c.

References __hash_log2(), __split_page(), calloc, htab::dir, htab::exsegs, hash_realloc(), htab::nsegs, and NULL.

Referenced by __addel().

{
   u_int32_t old_bucket, new_bucket;
   int dirsize, new_segnum, spare_ndx;

#ifdef HASH_STATISTICS
   hash_expansions++;
#endif
   new_bucket = ++hashp->MAX_BUCKET;
   old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK);

   new_segnum = new_bucket >> hashp->SSHIFT;

   /* Check if we need a new segment */
   if (new_segnum >= hashp->nsegs) {
      /* Check if we need to expand directory */
      if (new_segnum >= hashp->DSIZE) {
         /* Reallocate directory */
         dirsize = hashp->DSIZE * sizeof(SEGMENT *);
         if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1))
            return (-1);
         hashp->DSIZE = dirsize << 1;
      }
      if ((hashp->dir[new_segnum] =
          (SEGMENT)calloc(hashp->SGSIZE, sizeof(SEGMENT))) == NULL)
         return (-1);
      hashp->exsegs++;
      hashp->nsegs++;
   }
   /*
    * If the split point is increasing (MAX_BUCKET's log base 2
    * * increases), we need to copy the current contents of the spare
    * split bucket to the next bucket.
    */
   spare_ndx = __hash_log2(hashp->MAX_BUCKET + 1);
   if (spare_ndx > hashp->OVFL_POINT) {
      hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT];
      hashp->OVFL_POINT = spare_ndx;
   }

   if (new_bucket > (u_int32_t) hashp->HIGH_MASK) {
      /* Starting a new doubling */
      hashp->LOW_MASK = hashp->HIGH_MASK;
      hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK;
   }
   /* Relocate records to the new bucket */
   return (__split_page(hashp, old_bucket, new_bucket));
}

__hash_open()

DB* __hash_open	(	char *	file,
		int	flags,
		int	mode,
		const HASHINFO *	info,
		int	dflags
	)		const

Definition at line 96 of file hash.c.

References __buf_init(), alloc_segs(), BYTE_SHIFT, HASHINFO::cachesize, calloc, htab::cbucket, CHARKEY, DB_HASH, dbp, DEF_BUFSIZE, EFTYPE, errno, htab::flags, htab::fp, free(), hash_close(), hash_delete(), hash_fd(), hash_get(), hash_put(), hash_seq(), hash_sync(), HASHMAGIC, HASHVERSION, hdestroy(), htab::hdr, if(), init_hash(), malloc(), htab::mapp, htab::new_file, htab::nmaps, htab::nsegs, NULL, OLDHASHVERSION, RETURN_ERROR, htab::save_file, and swap_header().

Referenced by dbm_open(), dbopen(), and hcreate().

{
   HTAB *hashp;
   struct stat statbuf;
   DB *dbp;
   int bpages, hdrsize, new_table, nsegs, save_errno;

   if ((flags & O_ACCMODE) == O_WRONLY) {
      errno = EINVAL;
      return (NULL);
   }

   if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB))))
      return (NULL);
   hashp->fp = -1;

   /*
    * Even if user wants write only, we need to be able to read
    * the actual file, so we need to open it read/write. But, the
    * field in the hashp structure needs to be accurate so that
    * we can check accesses.
    */
   hashp->flags = flags;

   new_table = 0;
   if (!file || (flags & O_TRUNC) ||
       (stat(file, &statbuf) && (errno == ENOENT))) {
      if (errno == ENOENT)
         errno = 0; /* Just in case someone looks at errno */
      new_table = 1;
   }
   if (file) {
      if ((hashp->fp = open(file, flags, mode)) == -1)
         RETURN_ERROR(errno, error0);
      (void)fcntl(hashp->fp, F_SETFD, 1);
   }
   if (new_table) {
      if (!(hashp = init_hash(hashp, file, info)))
         RETURN_ERROR(errno, error1);
   } else {
      /* Table already exists */
      if (info && info->hash)
         hashp->hash = info->hash;
      else
         hashp->hash = __default_hash;

      hdrsize = read(hashp->fp, &hashp->hdr, sizeof(HASHHDR));
#if BYTE_ORDER == LITTLE_ENDIAN
      swap_header(hashp);
#endif
      if (hdrsize == -1)
         RETURN_ERROR(errno, error1);
      if (hdrsize != sizeof(HASHHDR))
         RETURN_ERROR(EFTYPE, error1);
      /* Verify file type, versions and hash function */
      if (hashp->MAGIC != HASHMAGIC)
         RETURN_ERROR(EFTYPE, error1);
#define  OLDHASHVERSION 1
      if (hashp->VERSION != HASHVERSION &&
          hashp->VERSION != OLDHASHVERSION)
         RETURN_ERROR(EFTYPE, error1);
      if (hashp->hash(CHARKEY, sizeof(CHARKEY))
          != (u_int32_t) hashp->H_CHARKEY)
         RETURN_ERROR(EFTYPE, error1);
      /*
       * Figure out how many segments we need.  Max_Bucket is the
       * maximum bucket number, so the number of buckets is
       * max_bucket + 1.
       */
      nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) /
          hashp->SGSIZE;
      hashp->nsegs = 0;
      if (alloc_segs(hashp, nsegs))
         /*
          * If alloc_segs fails, table will have been destroyed
          * and errno will have been set.
          */
         return (NULL);
      /* Read in bitmaps */
      bpages = (hashp->SPARES[hashp->OVFL_POINT] +
          (hashp->BSIZE << BYTE_SHIFT) - 1) >>
          (hashp->BSHIFT + BYTE_SHIFT);

      hashp->nmaps = bpages;
      (void)memset(&hashp->mapp[0], 0, bpages * sizeof(u_int32_t *));
   }

   /* Initialize Buffer Manager */
   if (info && info->cachesize)
      __buf_init(hashp, info->cachesize);
   else
      __buf_init(hashp, DEF_BUFSIZE);

   hashp->new_file = new_table;
   hashp->save_file = file && (hashp->flags & O_ACCMODE) != O_RDONLY;
   hashp->cbucket = -1;
   if (!(dbp = (DB *)malloc(sizeof(DB)))) {
      save_errno = errno;
      hdestroy(hashp);
      errno = save_errno;
      return (NULL);
   }
   dbp->internal = hashp;
   dbp->close = hash_close;
   dbp->del = hash_delete;
   dbp->fd = hash_fd;
   dbp->get = hash_get;
   dbp->put = hash_put;
   dbp->seq = hash_seq;
   dbp->sync = hash_sync;
   dbp->type = DB_HASH;

#ifdef DEBUG
   (void)fprintf(stderr,
"%s\n%s%x\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%x\n%s%x\n%s%d\n%s%d\n",
       "init_htab:",
       "TABLE POINTER   ", hashp,
       "BUCKET SIZE     ", hashp->BSIZE,
       "BUCKET SHIFT    ", hashp->BSHIFT,
       "DIRECTORY SIZE  ", hashp->DSIZE,
       "SEGMENT SIZE    ", hashp->SGSIZE,
       "SEGMENT SHIFT   ", hashp->SSHIFT,
       "FILL FACTOR     ", hashp->FFACTOR,
       "MAX BUCKET      ", hashp->MAX_BUCKET,
       "OVFL POINT        ", hashp->OVFL_POINT,
       "LAST FREED      ", hashp->LAST_FREED,
       "HIGH MASK       ", hashp->HIGH_MASK,
       "LOW  MASK       ", hashp->LOW_MASK,
       "NSEGS           ", hashp->nsegs,
       "NKEYS           ", hashp->NKEYS);
#endif
#ifdef HASH_STATISTICS
   hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0;
#endif
   return (dbp);

error1:
   if (hashp != NULL)
      (void)close(hashp->fp);

error0:
   free(hashp);
   errno = save_errno;
   return (NULL);
}

__P() [1/12]

static int alloc_segs __P ( (HTAB *, int)  )

static

__P() [2/12]

static int flush_meta __P ( (HTAB *)  )

static

__P() [3/12]

static int hash_access __P ( (HTAB *, ACTION, DBT *, DBT *)  )

static

__P() [4/12]

static int hash_close __P ( (DB *)  )

static

__P() [5/12]

static int hash_delete __P ( (const DB *, const DBT *, u_int32_t)  )

static

__P() [6/12]

static int hash_fd __P ( (const DB *)  )

static

__P() [7/12]

static int hash_put __P ( (const DB *, const DBT *, DBT *, u_int32_t)  )

static

__P() [8/12]

static void* hash_realloc __P ( (SEGMENT **, int, int)  )

static

__P() [9/12]

static int hash_seq __P ( (const DB *, DBT *, DBT *, u_int32_t)  )

static

__P() [10/12]

static int hash_sync __P ( (const DB *, u_int32_t)  )

static

__P() [11/12]

static HTAB* init_hash __P ( (HTAB *, const char *, const HASHINFO *)  )

static

__P() [12/12]

static void swap_header_copy __P ( (HASHHDR *, HASHHDR *)  )

static

alloc_segs()

static int alloc_segs ( HTAB *  hashp, int  nsegs  )

static

Definition at line 906 of file hash.c.

References calloc, htab::dir, errno, hdestroy(), htab::nsegs, and NULL.

Referenced by __hash_open(), and init_htab().

{
   register int i;
   register SEGMENT store;

   int save_errno;

   if ((hashp->dir =
       (SEGMENT *)calloc(hashp->DSIZE, sizeof(SEGMENT *))) == NULL) {
      save_errno = errno;
      (void)hdestroy(hashp);
      errno = save_errno;
      return (-1);
   }
   /* Allocate segments */
   if ((store =
       (SEGMENT)calloc(nsegs << hashp->SSHIFT, sizeof(SEGMENT))) == NULL) {
      save_errno = errno;
      (void)hdestroy(hashp);
      errno = save_errno;
      return (-1);
   }
   for (i = 0; i < nsegs; i++, hashp->nsegs++)
      hashp->dir[i] = &store[i << hashp->SSHIFT];
   return (0);
}

flush_meta()

static int flush_meta ( HTAB *  hashp )

static

Definition at line 486 of file hash.c.

References __put_page(), CHARKEY, EFTYPE, errno, htab::errnum, htab::fp, HASHMAGIC, HASHVERSION, htab::hdr, htab::mapp, NCACHED, htab::save_file, and swap_header_copy().

Referenced by hash_sync(), and hdestroy().

{
   HASHHDR *whdrp;
#if BYTE_ORDER == LITTLE_ENDIAN
   HASHHDR whdr;
#endif
   int fp, i, wsize;

   if (!hashp->save_file)
      return (0);
   hashp->MAGIC = HASHMAGIC;
   hashp->VERSION = HASHVERSION;
   hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY));

   fp = hashp->fp;
   whdrp = &hashp->hdr;
#if BYTE_ORDER == LITTLE_ENDIAN
   whdrp = &whdr;
   swap_header_copy(&hashp->hdr, whdrp);
#endif
   if ((lseek(fp, (off_t)0, SEEK_SET) == -1) ||
       ((wsize = write(fp, whdrp, sizeof(HASHHDR))) == -1))
      return (-1);
   else
      if (wsize != sizeof(HASHHDR)) {
         errno = EFTYPE;
         hashp->errnum = errno;
         return (-1);
      }
   for (i = 0; i < NCACHED; i++)
      if (hashp->mapp[i])
         if (__put_page(hashp, (char *)hashp->mapp[i],
            hashp->BITMAPS[i], 0, 1))
            return (-1);
   return (0);
}

hash_access()

static int hash_access ( HTAB *  hashp, ACTION  action, DBT *  key, DBT *  val  )

static

Definition at line 596 of file hash.c.

References __addel(), __big_return(), __call_hash(), __delpair(), __find_bigpair(), __find_last_page(), __get_buf(), ABNORMAL, BUF_PIN, DBT::data, ERROR, _bufhead::flags, HASH_DELETE, HASH_GET, HASH_PUT, HASH_PUTNEW, if(), NULL, OVFLPAGE, _bufhead::page, REAL_KEY, DBT::size, and SUCCESS.

Referenced by hash_delete(), hash_get(), and hash_put().

{
   register BUFHEAD *rbufp;
   BUFHEAD *bufp, *save_bufp;
   register u_int16_t *bp;
   register int n, ndx, off, size;
   register char *kp;
   u_int16_t pageno;

#ifdef HASH_STATISTICS
   hash_accesses++;
#endif

   off = hashp->BSIZE;
   size = key->size;
   kp = (char *)key->data;
   rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0);
   if (!rbufp)
      return (ERROR);
   save_bufp = rbufp;

   /* Pin the bucket chain */
   rbufp->flags |= BUF_PIN;
   for (bp = (u_int16_t *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
      if (bp[1] >= REAL_KEY) {
         /* Real key/data pair */
         if (size == off - *bp &&
             memcmp(kp, rbufp->page + *bp, size) == 0)
            goto found;
         off = bp[1];
#ifdef HASH_STATISTICS
         hash_collisions++;
#endif
         bp += 2;
         ndx += 2;
      } else if (bp[1] == OVFLPAGE) {
         rbufp = __get_buf(hashp, *bp, rbufp, 0);
         if (!rbufp) {
            save_bufp->flags &= ~BUF_PIN;
            return (ERROR);
         }
         /* FOR LOOP INIT */
         bp = (u_int16_t *)rbufp->page;
         n = *bp++;
         ndx = 1;
         off = hashp->BSIZE;
      } else if (bp[1] < REAL_KEY) {
         if ((ndx =
             __find_bigpair(hashp, rbufp, ndx, kp, size)) > 0)
            goto found;
         if (ndx == -2) {
            bufp = rbufp;
            if (!(pageno =
                __find_last_page(hashp, &bufp))) {
               ndx = 0;
               rbufp = bufp;
               break;   /* FOR */
            }
            rbufp = __get_buf(hashp, pageno, bufp, 0);
            if (!rbufp) {
               save_bufp->flags &= ~BUF_PIN;
               return (ERROR);
            }
            /* FOR LOOP INIT */
            bp = (u_int16_t *)rbufp->page;
            n = *bp++;
            ndx = 1;
            off = hashp->BSIZE;
         } else {
            save_bufp->flags &= ~BUF_PIN;
            return (ERROR);
         }
      }

   /* Not found */
   switch (action) {
   case HASH_PUT:
   case HASH_PUTNEW:
      if (__addel(hashp, rbufp, key, val)) {
         save_bufp->flags &= ~BUF_PIN;
         return (ERROR);
      } else {
         save_bufp->flags &= ~BUF_PIN;
         return (SUCCESS);
      }
   case HASH_GET:
   case HASH_DELETE:
   default:
      save_bufp->flags &= ~BUF_PIN;
      return (ABNORMAL);
   }

found:
   switch (action) {
   case HASH_PUTNEW:
      save_bufp->flags &= ~BUF_PIN;
      return (ABNORMAL);
   case HASH_GET:
      bp = (u_int16_t *)rbufp->page;
      if (bp[ndx + 1] < REAL_KEY) {
         if (__big_return(hashp, rbufp, ndx, val, 0))
            return (ERROR);
      } else {
         val->data = (u_char *)rbufp->page + (int)bp[ndx + 1];
         val->size = bp[ndx] - bp[ndx + 1];
      }
      break;
   case HASH_PUT:
      if ((__delpair(hashp, rbufp, ndx)) ||
          (__addel(hashp, rbufp, key, val))) {
         save_bufp->flags &= ~BUF_PIN;
         return (ERROR);
      }
      break;
   case HASH_DELETE:
      if (__delpair(hashp, rbufp, ndx))
         return (ERROR);
      break;
   default:
      abort();
   }
   save_bufp->flags &= ~BUF_PIN;
   return (SUCCESS);
}

hash_close()

static int hash_close ( DB *  dbp )

static

Definition at line 246 of file hash.c.

References ERROR, free(), hdestroy(), __db::internal, and retval.

Referenced by __hash_open().

{
   HTAB *hashp;
   int retval;

   if (!dbp)
      return (ERROR);

   hashp = (HTAB *)dbp->internal;
   retval = hdestroy(hashp);
   free(dbp);
   return (retval);
}

hash_delete()

static int hash_delete ( DB *  dbp, const DBT *  key, u_int32_t  flag  ) const

static

Definition at line 573 of file hash.c.

References errno, htab::errnum, ERROR, htab::flags, hash_access(), HASH_DELETE, if(), __db::internal, NULL, and R_CURSOR.

Referenced by __hash_open().

{
   HTAB *hashp;

   hashp = (HTAB *)dbp->internal;
   if (flag && flag != R_CURSOR) {
      hashp->errnum = errno = EINVAL;
      return (ERROR);
   }
   if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
      hashp->errnum = errno = EPERM;
      return (ERROR);
   }
   return (hash_access(hashp, HASH_DELETE, (DBT *)key, NULL));
}

hash_fd()

static int hash_fd ( DB *  dbp ) const

static

Definition at line 262 of file hash.c.

References errno, ERROR, htab::fp, if(), and __db::internal.

Referenced by __hash_open().

{
   HTAB *hashp;

   if (!dbp)
      return (ERROR);

   hashp = (HTAB *)dbp->internal;
   if (hashp->fp == -1) {
      errno = ENOENT;
      return (-1);
   }
   return (hashp->fp);
}

hash_get()

static int hash_get ( DB *  dbp, const DBT *  key, DBT *  data, u_int32_t  flag  ) const

static

Definition at line 534 of file hash.c.

References errno, htab::errnum, ERROR, hash_access(), HASH_GET, if(), and __db::internal.

Referenced by __hash_open().

{
   HTAB *hashp;

   hashp = (HTAB *)dbp->internal;
   if (flag) {
      hashp->errnum = errno = EINVAL;
      return (ERROR);
   }
   return (hash_access(hashp, HASH_GET, (DBT *)key, data));
}

hash_put()

static int hash_put ( DB *  dbp, DBT *  key, const DBT *  data, u_int32_t  flag  ) const

static

Definition at line 551 of file hash.c.

References errno, htab::errnum, ERROR, htab::flags, hash_access(), HASH_PUT, HASH_PUTNEW, if(), __db::internal, and R_NOOVERWRITE.

Referenced by __hash_open().

{
   HTAB *hashp;

   hashp = (HTAB *)dbp->internal;
   if (flag && flag != R_NOOVERWRITE) {
      hashp->errnum = errno = EINVAL;
      return (ERROR);
   }
   if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
      hashp->errnum = errno = EPERM;
      return (ERROR);
   }
   return (hash_access(hashp, flag == R_NOOVERWRITE ?
       HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data));
}

hash_realloc()

static void* hash_realloc ( SEGMENT **  p_ptr, int  oldsize, int  newsize  )

static

Definition at line 870 of file hash.c.

References free(), and malloc().

Referenced by __expand_table().

{
   register void *p;

   if ((p = malloc(newsize))) {
      memmove(p, *p_ptr, oldsize);
      memset((char *)p + oldsize, 0, newsize - oldsize);
      free(*p_ptr);
      *p_ptr = p;
   }
   return (p);
}

hash_seq()

static int hash_seq ( DB *  dbp, DBT *  key, DBT *  data, u_int32_t  flag  ) const

static

Definition at line 725 of file hash.c.

References __big_keydata(), __get_buf(), ABNORMAL, htab::cbucket, htab::cndx, htab::cpage, DBT::data, DEBUG, errno, htab::errnum, ERROR, if(), __db::internal, NULL, OVFLPAGE, _bufhead::page, R_FIRST, R_NEXT, REAL_KEY, DBT::size, and SUCCESS.

Referenced by __hash_open().

{
   register u_int32_t bucket;
   register BUFHEAD *bufp = NULL;
   HTAB *hashp;
   u_int16_t *bp, ndx;

   hashp = (HTAB *)dbp->internal;
   if (flag && flag != R_FIRST && flag != R_NEXT) {
      hashp->errnum = errno = EINVAL;
      return (ERROR);
   }
#ifdef HASH_STATISTICS
   hash_accesses++;
#endif
   if ((hashp->cbucket < 0) || (flag == R_FIRST)) {
      hashp->cbucket = 0;
      hashp->cndx = 1;
      hashp->cpage = NULL;
   }

   for (bp = NULL; !bp || !bp[0]; ) {
      if (!(bufp = hashp->cpage)) {
         for (bucket = hashp->cbucket;
             bucket <= (u_int32_t) hashp->MAX_BUCKET;
             bucket++, hashp->cndx = 1) {
            bufp = __get_buf(hashp, bucket, NULL, 0);
            if (!bufp)
               return (ERROR);
            hashp->cpage = bufp;
            bp = (u_int16_t *)bufp->page;
            if (bp[0])
               break;
         }
         hashp->cbucket = bucket;
         if (hashp->cbucket > hashp->MAX_BUCKET) {
            hashp->cbucket = -1;
            return (ABNORMAL);
         }
      } else
         bp = (u_int16_t *)hashp->cpage->page;

#ifdef DEBUG
      assert(bp);
      assert(bufp);
#endif
      while (bp[hashp->cndx + 1] == OVFLPAGE) {
         bufp = hashp->cpage =
             __get_buf(hashp, bp[hashp->cndx], bufp, 0);
         if (!bufp)
            return (ERROR);
         bp = (u_int16_t *)(bufp->page);
         hashp->cndx = 1;
      }
      if (!bp[0]) {
         hashp->cpage = NULL;
         ++hashp->cbucket;
      }
   }
   ndx = hashp->cndx;
   if (bp[ndx + 1] < REAL_KEY) {
      if (__big_keydata(hashp, bufp, key, data, 1))
         return (ERROR);
   } else {
      key->data = (u_char *)hashp->cpage->page + bp[ndx];
      key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
      data->data = (u_char *)hashp->cpage->page + bp[ndx + 1];
      data->size = bp[ndx] - bp[ndx + 1];
      ndx += 2;
      if (ndx > bp[0]) {
         hashp->cpage = NULL;
         hashp->cbucket++;
         hashp->cndx = 1;
      } else
         hashp->cndx = ndx;
   }
   return (SUCCESS);
}

hash_sync()

static int hash_sync ( DB *  dbp, u_int32_t  flags  ) const

static

Definition at line 457 of file hash.c.

References __buf_free(), errno, ERROR, flush_meta(), if(), __db::internal, htab::new_file, and htab::save_file.

Referenced by __hash_open().

{
   HTAB *hashp;

   if (flags != 0) {
      errno = EINVAL;
      return (ERROR);
   }

   if (!dbp)
      return (ERROR);

   hashp = (HTAB *)dbp->internal;
   if (!hashp->save_file)
      return (0);
   if (__buf_free(hashp, 0, 1) || flush_meta(hashp))
      return (ERROR);
   hashp->new_file = 0;
   return (0);
}

hdestroy()

static int hdestroy ( HTAB *  hashp )

static

Definition at line 397 of file hash.c.

References __buf_free(), htab::dir, errno, ERROR, htab::exsegs, flush_meta(), htab::fp, free(), htab::mapp, NCACHED, htab::nmaps, htab::nsegs, htab::save_file, and SUCCESS.

Referenced by __hash_open(), alloc_segs(), and hash_close().

{
   int i, save_errno;

   save_errno = 0;

#ifdef HASH_STATISTICS
   (void)fprintf(stderr, "hdestroy: accesses %ld collisions %ld\n",
       hash_accesses, hash_collisions);
   (void)fprintf(stderr, "hdestroy: expansions %ld\n",
       hash_expansions);
   (void)fprintf(stderr, "hdestroy: overflows %ld\n",
       hash_overflows);
   (void)fprintf(stderr, "keys %ld maxp %d segmentcount %d\n",
       hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs);

   for (i = 0; i < NCACHED; i++)
      (void)fprintf(stderr,
          "spares[%d] = %d\n", i, hashp->SPARES[i]);
#endif
   /*
    * Call on buffer manager to free buffers, and if required,
    * write them to disk.
    */
   if (__buf_free(hashp, 1, hashp->save_file))
      save_errno = errno;
   if (hashp->dir) {
      free(*hashp->dir);   /* Free initial segments */
      /* Free extra segments */
      while (hashp->exsegs--)
         free(hashp->dir[--hashp->nsegs]);
      free(hashp->dir);
   }
   if (flush_meta(hashp) && !save_errno)
      save_errno = errno;
   /* Free Bigmaps */
   for (i = 0; i < hashp->nmaps; i++)
      if (hashp->mapp[i])
         free(hashp->mapp[i]);

   if (hashp->fp != -1)
      (void)close(hashp->fp);

   free(hashp);

   if (save_errno) {
      errno = save_errno;
      return (ERROR);
   }
   return (SUCCESS);
}

init_hash()

static HTAB* init_hash ( HTAB *  hashp, const char *  file, const HASHINFO *  info  )

static

Definition at line 280 of file hash.c.

References __hash_log2(), BIG_ENDIAN, HASHINFO::bsize, BYTE_ORDER, DEF_BUCKET_SHIFT, DEF_BUCKET_SIZE, DEF_DIRSIZE, DEF_FFACTOR, DEF_SEGSIZE, DEF_SEGSIZE_SHIFT, errno, HASHINFO::ffactor, init_htab(), LITTLE_ENDIAN, HASHINFO::lorder, MAX_BSIZE, HASHINFO::nelem, and NULL.

Referenced by __hash_open().

{
#ifdef _STATBUF_ST_BLKSIZE
   struct stat statbuf;
#endif
   int nelem;

   nelem = 1;
   hashp->NKEYS = 0;
   hashp->LORDER = BYTE_ORDER;
   hashp->BSIZE = DEF_BUCKET_SIZE;
   hashp->BSHIFT = DEF_BUCKET_SHIFT;
   hashp->SGSIZE = DEF_SEGSIZE;
   hashp->SSHIFT = DEF_SEGSIZE_SHIFT;
   hashp->DSIZE = DEF_DIRSIZE;
   hashp->FFACTOR = DEF_FFACTOR;
   hashp->hash = __default_hash;
   memset(hashp->SPARES, 0, sizeof(hashp->SPARES));
   memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS));

   /* Fix bucket size to be optimal for file system */
#ifdef _STATBUF_ST_BLKSIZE
   if (file != NULL) {
      if (stat(file, &statbuf))
         return (NULL);
      hashp->BSIZE = statbuf.st_blksize;
      hashp->BSHIFT = __hash_log2(hashp->BSIZE);
   }
#endif

   if (info) {
      if (info->bsize) {
         /* Round pagesize up to power of 2 */
         hashp->BSHIFT = __hash_log2(info->bsize);
         hashp->BSIZE = 1 << hashp->BSHIFT;
         if (hashp->BSIZE > MAX_BSIZE) {
            errno = EINVAL;
            return (NULL);
         }
      }
      if (info->ffactor)
         hashp->FFACTOR = info->ffactor;
      if (info->hash)
         hashp->hash = info->hash;
      if (info->nelem)
         nelem = info->nelem;
      if (info->lorder) {
         if (info->lorder != BIG_ENDIAN &&
             info->lorder != LITTLE_ENDIAN) {
            errno = EINVAL;
            return (NULL);
         }
         hashp->LORDER = info->lorder;
      }
   }
   /* init_htab should destroy the table and set errno if it fails */
   if (init_htab(hashp, nelem))
      return (NULL);
   else
      return (hashp);
}

init_htab()

static int init_htab ( HTAB *  hashp, int  nelem  )

static

Definition at line 351 of file hash.c.

References __hash_log2(), __ibitmap(), alloc_segs(), MAX, MINHDRSIZE, and OADDR_OF.

Referenced by init_hash().

{
   register int nbuckets, nsegs;
   int l2;

   /*
    * Divide number of elements by the fill factor and determine a
    * desired number of buckets.  Allocate space for the next greater
    * power of two number of buckets.
    */
   nelem = (nelem - 1) / hashp->FFACTOR + 1;

   l2 = __hash_log2(MAX(nelem, 2));
   nbuckets = 1 << l2;

   hashp->SPARES[l2] = l2 + 1;
   hashp->SPARES[l2 + 1] = l2 + 1;
   hashp->OVFL_POINT = l2;
   hashp->LAST_FREED = 2;

   /* First bitmap page is at: splitpoint l2 page offset 1 */
   if (__ibitmap(hashp, OADDR_OF(l2, 1), l2 + 1, 0))
      return (-1);

   hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1;
   hashp->HIGH_MASK = (nbuckets << 1) - 1;
   hashp->HDRPAGES = ((MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >>
       hashp->BSHIFT) + 1;

   nsegs = (nbuckets - 1) / hashp->SGSIZE + 1;
   nsegs = 1 << __hash_log2(nsegs);

   if (nsegs > hashp->DSIZE)
      hashp->DSIZE = nsegs;
   return (alloc_segs(hashp, nsegs));
}

swap_header()

static void swap_header ( HTAB *  hashp )

static

Definition at line 969 of file hash.c.

References hashhdr::bitmaps, hashhdr::bshift, hashhdr::bsize, hashhdr::dsize, hashhdr::ffactor, hashhdr::h_charkey, htab::hdr, hashhdr::hdrpages, hashhdr::high_mask, hashhdr::last_freed, hashhdr::lorder, hashhdr::low_mask, hashhdr::magic, hashhdr::max_bucket, NCACHED, hashhdr::nkeys, hashhdr::ovfl_point, hashhdr::spares, hashhdr::sshift, hashhdr::ssize, and hashhdr::version.

Referenced by __hash_open().

{
   HASHHDR *hdrp;
   int i;

   hdrp = &hashp->hdr;

   M_32_SWAP(hdrp->magic);
   M_32_SWAP(hdrp->version);
   M_32_SWAP(hdrp->lorder);
   M_32_SWAP(hdrp->bsize);
   M_32_SWAP(hdrp->bshift);
   M_32_SWAP(hdrp->dsize);
   M_32_SWAP(hdrp->ssize);
   M_32_SWAP(hdrp->sshift);
   M_32_SWAP(hdrp->ovfl_point);
   M_32_SWAP(hdrp->last_freed);
   M_32_SWAP(hdrp->max_bucket);
   M_32_SWAP(hdrp->high_mask);
   M_32_SWAP(hdrp->low_mask);
   M_32_SWAP(hdrp->ffactor);
   M_32_SWAP(hdrp->nkeys);
   M_32_SWAP(hdrp->hdrpages);
   M_32_SWAP(hdrp->h_charkey);
   for (i = 0; i < NCACHED; i++) {
      M_32_SWAP(hdrp->spares[i]);
      M_16_SWAP(hdrp->bitmaps[i]);
   }
}

swap_header_copy()

static void swap_header_copy ( HASHHDR *  srcp, HASHHDR *  destp  )

static

Definition at line 940 of file hash.c.

References hashhdr::bitmaps, hashhdr::bshift, hashhdr::bsize, hashhdr::dsize, hashhdr::ffactor, hashhdr::h_charkey, hashhdr::hdrpages, hashhdr::high_mask, hashhdr::last_freed, hashhdr::lorder, hashhdr::low_mask, hashhdr::magic, hashhdr::max_bucket, NCACHED, hashhdr::nkeys, hashhdr::ovfl_point, hashhdr::spares, hashhdr::sshift, hashhdr::ssize, and hashhdr::version.

Referenced by flush_meta().

{
   int i;

   P_32_COPY(srcp->magic, destp->magic);
   P_32_COPY(srcp->version, destp->version);
   P_32_COPY(srcp->lorder, destp->lorder);
   P_32_COPY(srcp->bsize, destp->bsize);
   P_32_COPY(srcp->bshift, destp->bshift);
   P_32_COPY(srcp->dsize, destp->dsize);
   P_32_COPY(srcp->ssize, destp->ssize);
   P_32_COPY(srcp->sshift, destp->sshift);
   P_32_COPY(srcp->ovfl_point, destp->ovfl_point);
   P_32_COPY(srcp->last_freed, destp->last_freed);
   P_32_COPY(srcp->max_bucket, destp->max_bucket);
   P_32_COPY(srcp->high_mask, destp->high_mask);
   P_32_COPY(srcp->low_mask, destp->low_mask);
   P_32_COPY(srcp->ffactor, destp->ffactor);
   P_32_COPY(srcp->nkeys, destp->nkeys);
   P_32_COPY(srcp->hdrpages, destp->hdrpages);
   P_32_COPY(srcp->h_charkey, destp->h_charkey);
   for (i = 0; i < NCACHED; i++) {
      P_32_COPY(srcp->spares[i], destp->spares[i]);
      P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]);
   }
}