mariadb/newbrt/fifo.h

#ifndef FIFO_H
#define FIFO_H
#ident "$Id$"
#ident "Copyright (c) 2007-2010 Tokutek Inc.  All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."

#include "brttypes.h"
#include "xids-internal.h"
#include "xids.h"

#if defined(__cplusplus) || defined(__cilkplusplus)
extern "C" {
#endif

// If the fifo_entry is unpacked, the compiler aligns the xids array and we waste a lot of space
#if TOKU_WINDOWS
#pragma pack(push, 1)
#endif

struct __attribute__((__packed__)) fifo_entry {
    unsigned int keylen;
    unsigned int vallen;
    unsigned char type;
    bool          is_fresh;
    MSN           msn;
    XIDS_S        xids_s;
};

#if TOKU_WINDOWS
#pragma pack(pop)
#endif

typedef struct fifo *FIFO;

int toku_fifo_create(FIFO *);

void toku_fifo_free(FIFO *);

// Use the size hint to size the storage for the fifo entries in anticipation of putting a bunch of them
// into the fifo.
void toku_fifo_size_hint(FIFO, size_t size_hint);

void toku_fifo_size_is_stabilized(FIFO);
// Effect: Tell the FIFO that we may have just inserted or removed a bunch of stuff, and now may be a good time to resize memory.

int toku_fifo_n_entries(FIFO);

int toku_fifo_enq_cmdstruct (FIFO fifo, const BRT_MSG cmd, bool is_fresh, long *dest);

int toku_fifo_enq (FIFO, const void *key, ITEMLEN keylen, const void *data, ITEMLEN datalen, int type, MSN msn, XIDS xids, bool is_fresh, long *dest);

int toku_fifo_peek (FIFO, bytevec *key, ITEMLEN *keylen, bytevec *data, ITEMLEN *datalen, u_int32_t *type, MSN *msn, XIDS *xids, bool *is_fresh);

// int toku_fifo_peek_cmdstruct (FIFO, BRT_MSG, DBT*, DBT*); // fill in the BRT_MSG, using the two DBTs for the DBT part.
int toku_fifo_deq(FIFO);  // we cannot deq items anymore, since their offsets are indexed.
                          // THIS ONLY REMAINS FOR TESTING, DO NOT USE IT IN CODE
int toku_fifo_empty(FIFO);  // don't deallocate the memory for the fifo

unsigned long toku_fifo_memory_size_in_use(FIFO fifo);  // return how much memory the fifo uses.

unsigned long toku_fifo_memory_size(FIFO); // return how much memory fifo has allocated

//These two are problematic, since I don't want to malloc() the bytevecs, but dequeueing the fifo frees the memory.
//int toku_fifo_peek_deq (FIFO, bytevec *key, ITEMLEN *keylen, bytevec *data, ITEMLEN *datalen, u_int32_t *type, TXNID *xid);
//int toku_fifo_peek_deq_cmdstruct (FIFO, BRT_MSG, DBT*, DBT*); // fill in the BRT_MSG, using the two DBTs for the DBT part.
void toku_fifo_iterate (FIFO, void(*f)(bytevec key,ITEMLEN keylen,bytevec data,ITEMLEN datalen,int type, MSN msn, XIDS xids, bool is_fresh, void*), void*);

#define FIFO_ITERATE(fifo,keyvar,keylenvar,datavar,datalenvar,typevar,msnvar,xidsvar,is_freshvar,body) ({ \
  for (int fifo_iterate_off = toku_fifo_iterate_internal_start(fifo);                          \
       toku_fifo_iterate_internal_has_more(fifo, fifo_iterate_off);                        \
       fifo_iterate_off = toku_fifo_iterate_internal_next(fifo, fifo_iterate_off)) {       \
      struct fifo_entry *e = toku_fifo_iterate_internal_get_entry(fifo, fifo_iterate_off); \
      ITEMLEN keylenvar = e->keylen;                                                       \
      ITEMLEN datalenvar = e->vallen;                                                 \
      enum brt_msg_type typevar = (enum brt_msg_type)e->type;                         \
      MSN     msnvar  = e->msn;                                                       \
      XIDS    xidsvar = &e->xids_s;                                                   \
      bytevec keyvar  = xids_get_end_of_array(xidsvar);                               \
      bytevec datavar = (const u_int8_t*)keyvar + e->keylen;                          \
      bool is_freshvar = e->is_fresh;                                                 \
      body;	\
  } })

// Internal functions for the iterator.
int toku_fifo_iterate_internal_start(FIFO fifo);
int toku_fifo_iterate_internal_has_more(FIFO fifo, int off);
int toku_fifo_iterate_internal_next(FIFO fifo, int off);
struct fifo_entry * toku_fifo_iterate_internal_get_entry(FIFO fifo, int off);

DBT *fill_dbt_for_fifo_entry(DBT *dbt, const struct fifo_entry *entry);
const struct fifo_entry *toku_fifo_get_entry(FIFO fifo, long off);

#if defined(__cplusplus) || defined(__cilkplusplus)
};
#endif

#endif