qam.h

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/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1999, 2000
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: qam_8h-source.html,v 1.1 2008/06/08 10:21:36 sebdiaz Exp $
 */

/*
 * QAM data elements: a status field and the data.
 */
typedef struct _qamdata {
        u_int8_t  flags;        /* 00: delete bit. */
#define QAM_VALID       0x01
#define QAM_SET         0x02
        u_int8_t  data[1];      /* Record. */
} QAMDATA;

struct __queue;         typedef struct __queue QUEUE;
struct __qcursor;       typedef struct __qcursor QUEUE_CURSOR;

struct __qcursor {
        /* struct __dbc_internal */
        __DBC_INTERNAL

        /* Queue private part */

        /* Per-thread information: queue private. */
        db_recno_t       start;         /* start record number. */
        db_recno_t       recno;         /* Current record number. */

        u_int32_t        flags;
};

/*
 * The in-memory, per-tree queue data structure.
 */
struct __queue {
        db_pgno_t q_meta;               /* Database meta-data page. */
        db_pgno_t q_root;               /* Database root page. */

        int       re_pad;               /* Fixed-length padding byte. */
        u_int32_t re_len;               /* Length for fixed-length records. */
        u_int32_t rec_page;             /* records per page */
};

/*
 * Caculate the page number of a recno
 *
 * Number of records per page =
 *      Divide the available space on the page by the record len + header.
 *
 * Page number for record =
 *      divide the physical record number by the records per page
 *      add the root page number
 *      For now the root page will always be 1, but we might want to change
 *      in the future (e.g. multiple fixed len queues per file).
 *
 * Index of record on page =
 *      physical record number, less the logical pno times records/page
 */
#define CALC_QAM_RECNO_PER_PAGE(dbp)                                    \
    (((dbp)->pgsize - sizeof(QPAGE)) /                                  \
    ALIGN(((QUEUE *)(dbp)->q_internal)->re_len +                        \
    sizeof(QAMDATA) - SSZA(QAMDATA, data), sizeof(u_int32_t)))

#define QAM_RECNO_PER_PAGE(dbp) (((QUEUE*)(dbp)->q_internal)->rec_page)

#define QAM_RECNO_PAGE(dbp, start, recno)                               \
    (((QUEUE *)(dbp)->q_internal)->q_root                               \
    + (((recno) - (start)) / QAM_RECNO_PER_PAGE(dbp)))

#define QAM_RECNO_INDEX(dbp, pgno, start, recno)                        \
    (((recno) - (start)) - (QAM_RECNO_PER_PAGE(dbp)                     \
    * (pgno - ((QUEUE *)(dbp)->q_internal)->q_root)))

#define QAM_GET_RECORD(dbp, page, index)                                \
    ((QAMDATA *)((u_int8_t *)(page) +                                   \
    sizeof(QPAGE) + (ALIGN(sizeof(QAMDATA) - SSZA(QAMDATA, data) +      \
    ((QUEUE *)(dbp)->q_internal)->re_len, sizeof(u_int32_t)) * index)))

/*
 * Log opcodes for the mvptr routine.
 */
#define QAM_SETFIRST            0x01
#define QAM_SETCUR              0x02

#include "qam_auto.h"
#include "qam_ext.h"

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