H5HGpkg.h

00001 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
00002  * Copyright by The HDF Group.                                               *
00003  * Copyright by the Board of Trustees of the University of Illinois.         *
00004  * All rights reserved.                                                      *
00005  *                                                                           *
00006  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
00007  * terms governing use, modification, and redistribution, is contained in    *
00008  * the files COPYING and Copyright.html.  COPYING can be found at the root   *
00009  * of the source code distribution tree; Copyright.html can be found at the  *
00010  * root level of an installed copy of the electronic HDF5 document set and   *
00011  * is linked from the top-level documents page.  It can also be found at     *
00012  * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
00013  * access to either file, you may request a copy from help@hdfgroup.org.     *
00014  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
00015 
00016 /*
00017  * Programmer: Quincey Koziol <koziol@ncsa.uiuc.edu>
00018  *             Wednesday, July 9, 2003
00019  *
00020  * Purpose:     This file contains declarations which are visible
00021  *              only within the H5HG package. Source files outside the
00022  *              H5HG package should include H5HGprivate.h instead.
00023  */
00024 #ifndef H5HG_PACKAGE
00025 #error "Do not include this file outside the H5HG package!"
00026 #endif
00027 
00028 #ifndef _H5HGpkg_H
00029 #define _H5HGpkg_H
00030 
00031 /* Get package's private header */
00032 #include "H5HGprivate.h"
00033 
00034 /* Other private headers needed by this file */
00035 #include "H5ACprivate.h"        /* Metadata cache                       */
00036 #include "H5FLprivate.h"        /* Free lists                           */
00037 
00038 
00039 /*****************************/
00040 /* Package Private Variables */
00041 /*****************************/
00042 
00043 /* The cache subclass */
00044 H5_DLLVAR const H5AC_class_t H5AC_GHEAP[1];
00045 
00046 /* Declare extern the free list to manage the H5HG_t struct */
00047 H5FL_EXTERN(H5HG_heap_t);
00048 
00049 /* Declare extern the free list to manage sequences of H5HG_obj_t's */
00050 H5FL_SEQ_EXTERN(H5HG_obj_t);
00051 
00052 /* Declare extern the PQ free list to manage heap chunks */
00053 H5FL_BLK_EXTERN(gheap_chunk);
00054 
00055 
00056 /**************************/
00057 /* Package Private Macros */
00058 /**************************/
00059 
00060 /*
00061  * Global heap collection version.
00062  */
00063 #define H5HG_VERSION    1
00064 
00065 /*
00066  * All global heap collections are at least this big.  This allows us to read
00067  * most collections with a single read() since we don't have to read a few
00068  * bytes of header to figure out the size.  If the heap is larger than this
00069  * then a second read gets the rest after we've decoded the header.
00070  */
00071 #define H5HG_MINSIZE    4096
00072 
00073 /*
00074  * Maximum length of the CWFS list, the list of remembered collections that
00075  * have free space.
00076  */
00077 #define H5HG_NCWFS      16
00078 
00079 /*
00080  * Pad all global heap messages to a multiple of eight bytes so we can load
00081  * the entire collection into memory and operate on it there.  Eight should
00082  * be sufficient for machines that have alignment constraints because our
00083  * largest data type is eight bytes.
00084  */
00085 #define H5HG_ALIGNMENT  8
00086 #define H5HG_ALIGN(X)   (H5HG_ALIGNMENT*(((X)+H5HG_ALIGNMENT-1)/              \
00087                                          H5HG_ALIGNMENT))
00088 #define H5HG_ISALIGNED(X) ((X)==H5HG_ALIGN(X))
00089 
00090 /*
00091  * The size of the collection header, always a multiple of the alignment so
00092  * that the stuff that follows the header is aligned.
00093  */
00094 #define H5HG_SIZEOF_HDR(f)                                                    \
00095     H5HG_ALIGN(4 +                      /*magic number          */            \
00096                1 +                      /*version number        */            \
00097                3 +                      /*reserved              */            \
00098                H5F_SIZEOF_SIZE(f))      /*collection size       */
00099 
00100 /*
00101  * The overhead associated with each object in the heap, always a multiple of
00102  * the alignment so that the stuff that follows the header is aligned.
00103  */
00104 #define H5HG_SIZEOF_OBJHDR(f)                                                 \
00105     H5HG_ALIGN(2 +                      /*object id number      */            \
00106                2 +                      /*reference count       */            \
00107                4 +                      /*reserved              */            \
00108                H5F_SIZEOF_SIZE(f))      /*object data size      */
00109 
00110 /*
00111  * The initial guess for the number of messages in a collection.  We assume
00112  * that all objects in that collection are zero length, giving the maximum
00113  * possible number of objects in the collection.  The collection itself has
00114  * some overhead and each message has some overhead.  The `+2' accounts for
00115  * rounding and for the free space object.
00116  */
00117 #define H5HG_NOBJS(f,z) (int)((((z)-H5HG_SIZEOF_HDR(f))/                      \
00118                                H5HG_SIZEOF_OBJHDR(f)+2))
00119 
00120 
00121 /****************************/
00122 /* Package Private Typedefs */
00123 /****************************/
00124 
00125 typedef struct H5HG_obj_t {
00126     int         nrefs;          /*reference count               */
00127     size_t              size;           /*total size of object          */
00128     uint8_t             *begin;         /*ptr to object into heap->chunk*/
00129 } H5HG_obj_t;
00130 
00131 struct H5HG_heap_t {
00132     H5AC_info_t cache_info; /* Information for H5AC cache functions, _must_ be */
00133                             /* first field in structure */
00134     haddr_t             addr;           /*collection address            */
00135     size_t              size;           /*total size of collection      */
00136     uint8_t             *chunk;         /*the collection, incl. header  */
00137     size_t              nalloc;         /*numb object slots allocated   */
00138     size_t              nused;          /*number of slots used          */
00139                                         /* If this value is >65535 then all indices */
00140                                         /* have been used at some time and the */
00141                                         /* correct new index should be searched for */
00142     H5HG_obj_t  *obj;           /*array of object descriptions  */
00143 };
00144 
00145 /******************************/
00146 /* Package Private Prototypes */
00147 /******************************/
00148 H5_DLL herr_t H5HG_dest(H5F_t *f, H5HG_heap_t *heap);
00149 
00150 #endif /* _H5HGpkg_H */
00151