Innodb 中 rec_get_offsets 的使用注意点

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/******************************************************/``/**

The following function determines the offsets to each field

in the record.  It can reuse a previously allocated array.

@return the new offsets */

UNIV_INTERN

ulint*

rec_get_offsets_func(

/*=================*/

    ``const rec_t*        rec,    ``/*!< in: physical record */

    ``const dict_index_t* index,  ``/*!< in: record descriptor */

    ``ulint*          offsets,``/*!< in/out: array consisting of

                    ``offsets[0] allocated elements,

                    ``or an array from rec_get_offsets(),

                    ``or NULL */

    ``ulint           n_fields,``/*!< in: maximum number of

                    ``initialized fields

                     ``(ULINT_UNDEFINED if all fields) */

    ``mem_heap_t**        heap,   ``/*!< in/out: memory heap */

    ``const char``*     file,   ``/*!< in: file name where called */

    ``ulint           line);  ``/*!< in: line number where called */

#define rec_get_offsets(rec,index,offsets,n,heap)  

    ``rec_get_offsets_func(rec,index,offsets,n,heap,__FILE__,__LINE__)

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ulint       offsets_[REC_OFFS_NORMAL_SIZE];

 ``ulint*      offsets             = offsets_;

 ``mem_heap_t* heap                = NULL;

 ``row_cache_chain_t* chain = NULL;

 ``rec_offs_init(offsets_);

//TODO Someting

 ``if (UNIV_LIKELY_NULL(heap)) {

     ``mem_heap_free(heap);

 ``}

 ``return``;

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if (UNIV_LIKELY_NULL(heap)) {

        ``mem_heap_free(heap);

    ``}