通過一個簡單的ABAP報表窺探ABAP記憶體分配和管理機制
- 2020 年 1 月 21 日
- 筆記
REPORT zhelloworld. PARAMETERS: clear TYPE c as CHECKBOX DEFAULT abap_false. TYPES: tt_table TYPE TABLE OF tadir WITH KEY pgmid object. DATA: lt_result TYPE TABLE OF tadir, lt_total TYPE TABLE OF tadir, lr_result TYPE REF TO tt_table. DATA: c1 TYPE cursor. OPEN CURSOR @c1 FOR SELECT * FROM tadir. DO. WRITE: / |Round: { sy-index } | COLOR COL_NEGATIVE. CREATE DATA lr_result. FETCH NEXT CURSOR @c1 INTO TABLE @lr_result->* PACKAGE SIZE 800000. IF sy-subrc <> 0. EXIT. ENDIF. APPEND LINES OF lr_result->* TO lt_total. cl_abap_memory_utilities=>get_memory_size_of_object( EXPORTING object = lt_total IMPORTING bound_size_alloc = DATA(bound_alloc) bound_size_used = DATA(bound_used) ). WRITE: / 'bound alloc:' , bound_alloc. WRITE: / 'bound used:' , bound_used. cl_abap_memory_utilities=>get_total_used_size( IMPORTING size = DATA(lv_before_size) ). WRITE: / |Total size before GC: { lv_before_size }| COLOR COL_POSITIVE. IF clear = abap_true. CLEAR: lr_result->*, lt_result, lr_result. ENDIF. "cl_abap_memory_utilities=>do_garbage_collection( ). cl_abap_memory_utilities=>get_total_used_size( IMPORTING size = DATA(lv_after_size) ). WRITE: / |Total size after GC: { lv_after_size }| COLOR COL_GROUP. DATA(rate) = ( lv_before_size - lv_after_size ) * 100 / lv_before_size. WRITE: / |Freed rate: { rate }%| COLOR COL_TOTAL. ENDDO. WRITE: / lines( lt_total ).
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