# 2020q3 Homework3 (dict)
contributed by < `joey3639570` >
###### tags: `進階電腦系統理論與實作`
### 20201003 紀錄

`make test`

 Performance counter stats for './test_common --bench CPY s Tai' (100 runs):

          644,6378      cache-misses              #   59.385 % of all cache refs      ( +-  0.14% )
         1085,5241      cache-references                                              ( +-  0.16% )
       5,8774,0970      instructions              #    0.99  insn per cycle           ( +-  0.02% )
       5,9494,2583      cycles                                                        ( +-  0.12% )

           0.19405 +- 0.00109 seconds time elapsed  ( +-  0.56% )

Performance counter stats for './test_common --bench REF s Tai' (100 runs):

          640,4946      cache-misses              #   58.638 % of all cache refs      ( +-  0.29% )
         1092,2802      cache-references                                              ( +-  0.25% )
       5,5421,2901      instructions              #    0.93  insn per cycle           ( +-  0.00% )
       5,9316,0349      cycles                                                        ( +-  0.34% )

          0.192271 +- 0.000661 seconds time elapsed  ( +-  0.34% )

`make bench`

COPY mechanism
test_common => choice: find words matching prefix (at least 1 char):   Tai - searched prefix in 0.000165 sec
REFERENCE mechanism
test_common => choice: find words matching prefix (at least 1 char):   Tai - searched prefix in 0.000212 sec

## 視覺化 ternary search tree (TST) + bloom filter 的效能表現並分析

## CPY V.S. REF
>- copy 機制 (CPY): 傳入 tst_ins_del 的字串地址所表示的值隨時會被覆寫，因此 eqkid 需要 malloc 新空間將其 copy 存起來;
>- reference 機制 (REF): 傳進來的字串地址所表示的值一直屬於該字串，以此可將其當作 reference 直接存起來，不用透過 malloc 新空間。

## Memory Pool

if (CPYmask) {
    /* memory pool */
    malloc(poolsize * sizeof(char));
    Top = pool;
}