usr/src/lib/libnisdb/db_pickle.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  *      db_pickle.h
  24  *
  25  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  26  * Use is subject to license terms.
  27  */
  28
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"
  30
  31 #ifndef PICKLE_H
  32 #define PICKLE_H
  33
  34 #include "nisdb_rw.h"
  35
  36 /*
  37  * 'pickle' is the package for storing data structures into files.
  38  * 'pickle_file' is the base class.  Classes that inherit this base
  39  * class need to instantiate the virtual function 'dump'.
  40  */
  41
  42 enum pickle_mode {
  43         PICKLE_READ, PICKLE_WRITE, PICKLE_APPEND
  44 };
  45
  46 typedef enum pickle_mode pickle_mode;
  47
  48 typedef void* pptr;             /* pickle pointer */
  49
  50 class pickle_file {
  51     protected:
  52         FILE *file;             /* file handle */
  53         pickle_mode mode;
  54         XDR xdr;
  55         char *filename;
  56         STRUCTRWLOCK(pickle);
  57     public:
  58
  59         /* Constructor.  Creates pickle_file with given name and mode. */
  60         pickle_file(char *, pickle_mode);
  61
  62         ~pickle_file()  { delete filename; DESTROYRW(pickle); }
  63
  64         /*
  65          * Opens pickle_file with mode specified with constructor.
  66          * Returns TRUE if open was successful; FALSE otherwise.
  67          */
  68         bool_t open();
  69
  70         /* Closes pickle_file.  Returns 0 if successful; -1 otherwise. */
  71         int close();
  72
  73         /*
  74          * dump or load data structure to/from 'filename' using function 'f'.
  75          * dump/load is determined by 'mode' with which pickle_file was created.
  76          * Returns 0 if successful; 1 if file cannot be opened in mode
  77          * specified; -1 if transfer failed do to encoding/decoding errors.
  78          */
  79         int transfer(pptr, bool_t (*f) (XDR*, pptr));
  80
  81         /* Exclusive access */
  82         int acqexcl(void) {
  83                 return (WLOCK(pickle));
  84         }
  85
  86         int relexcl(void) {
  87                 return (WULOCK(pickle));
  88         }
  89 };
  90 #endif /* PICKLE_H */