Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitd8cc161

Browse files
committed
Minor additional improvements for ecpglib/prepare.c.
Avoid allocating never-used entries in stmtCacheEntries[], other than theintentionally-unused zero'th entry. Tie the array size directly to thebucket count and size, rather than having undocumented dependencies betweenthree magic constants. Fix the hash calculation to be platform-independent--- notably, it was sensitive to the signed'ness of "char" before, not tomention having an unnecessary hard-wired dependency on the existence andsize of type "long long". (The lack of complaints says it's been a longtime since anybody tried to build PG on a compiler without "long long",and certainly with the requirement for C99 this isn't a live bug anymore.But it's still not per project coding style.) Fix ecpg_auto_prepare'snew-cache-entry path so that it increments the exec count for the newcache entry not the dummy zero'th entry.The last of those is an actual bug, though one of little consequence;the rest is mostly future-proofing and neatnik-ism. Doesn't seemnecessary to back-patch.
1 parente7eb07f commitd8cc161

File tree

2 files changed

+27
-16
lines changed

2 files changed

+27
-16
lines changed

‎src/interfaces/ecpg/ecpglib/prepare.c

Lines changed: 22 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -13,7 +13,17 @@
1313

1414
#defineSTMTID_SIZE 32
1515

16-
#defineN_STMTCACHE_ENTRIES 16384
16+
/*
17+
* The statement cache contains stmtCacheNBuckets hash buckets, each
18+
* having stmtCacheEntPerBucket entries, which we recycle as needed,
19+
* giving up the least-executed entry in the bucket.
20+
* stmtCacheEntries[0] is never used, so that zero can be a "not found"
21+
* indicator.
22+
*/
23+
#definestmtCacheNBuckets2039/* should be a prime number */
24+
#definestmtCacheEntPerBucket8
25+
26+
#definestmtCacheArraySize (stmtCacheNBuckets * stmtCacheEntPerBucket + 1)
1727

1828
typedefstruct
1929
{
@@ -25,8 +35,6 @@ typedef struct
2535
}stmtCacheEntry;
2636

2737
staticintnextStmtID=1;
28-
staticconstintstmtCacheNBuckets=2039;/* # buckets - a prime # */
29-
staticconstintstmtCacheEntPerBucket=8;/* # entries/bucket */
3038
staticstmtCacheEntry*stmtCacheEntries=NULL;
3139

3240
staticbooldeallocate_one(intlineno,enumCOMPAT_MODEc,structconnection*con,
@@ -330,7 +338,7 @@ HashStmt(const char *ecpgQuery)
330338
bucketNo,
331339
hashLeng,
332340
stmtLeng;
333-
long longhashVal,
341+
uint64hashVal,
334342
rotVal;
335343

336344
stmtLeng=strlen(ecpgQuery);
@@ -341,16 +349,17 @@ HashStmt(const char *ecpgQuery)
341349
hashVal=0;
342350
for (stmtIx=0;stmtIx<hashLeng;++stmtIx)
343351
{
344-
hashVal=hashVal+ (int)ecpgQuery[stmtIx];
352+
hashVal=hashVal+ (unsignedchar)ecpgQuery[stmtIx];
353+
/* rotate 32-bit hash value left 13 bits */
345354
hashVal=hashVal <<13;
346-
rotVal= (hashVal&0x1fff00000000LL) >>32;
347-
hashVal= (hashVal&0xffffffffLL) |rotVal;
355+
rotVal= (hashVal&UINT64CONST(0x1fff00000000)) >>32;
356+
hashVal= (hashVal&UINT64CONST(0xffffffff)) |rotVal;
348357
}
349358

350359
bucketNo=hashVal %stmtCacheNBuckets;
351-
bucketNo+=1;/* don't use bucket # 0 */
352360

353-
return (bucketNo*stmtCacheEntPerBucket);
361+
/* Add 1 so that array entry 0 is never used */
362+
returnbucketNo*stmtCacheEntPerBucket+1;
354363
}
355364

356365
/*
@@ -451,7 +460,7 @@ AddStmtToCache(int lineno,/* line # of statement */
451460
if (stmtCacheEntries==NULL)
452461
{
453462
stmtCacheEntries= (stmtCacheEntry*)
454-
ecpg_alloc(sizeof(stmtCacheEntry)*N_STMTCACHE_ENTRIES,lineno);
463+
ecpg_alloc(sizeof(stmtCacheEntry)*stmtCacheArraySize,lineno);
455464
if (stmtCacheEntries==NULL)
456465
return-1;
457466
}
@@ -534,7 +543,9 @@ ecpg_auto_prepare(int lineno, const char *connection_name, const int compat, cha
534543

535544
if (!ECPGprepare(lineno,connection_name,0,stmtID,query))
536545
return false;
537-
if (AddStmtToCache(lineno,stmtID,connection_name,compat,query)<0)
546+
547+
entNo=AddStmtToCache(lineno,stmtID,connection_name,compat,query);
548+
if (entNo<0)
538549
return false;
539550

540551
*name=ecpg_strdup(stmtID,lineno);

‎src/interfaces/ecpg/test/expected/preproc-autoprep.stderr

Lines changed: 5 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -30,7 +30,7 @@
3030
[NO_PID]: sqlca: code: 0, state: 00000
3131
[NO_PID]: ecpg_process_output on line 24: OK: INSERT 0 1
3232
[NO_PID]: sqlca: code: 0, state: 00000
33-
[NO_PID]: ecpg_auto_prepare on line 26: statement found in cache; entry1640
33+
[NO_PID]: ecpg_auto_prepare on line 26: statement found in cache; entry1633
3434
[NO_PID]: sqlca: code: 0, state: 00000
3535
[NO_PID]: ecpg_execute on line 26: query: insert into T values ( 1 , $1 ); with 1 parameter(s) on connection ecpg1_regression
3636
[NO_PID]: sqlca: code: 0, state: 00000
@@ -168,7 +168,7 @@
168168
[NO_PID]: sqlca: code: 0, state: 00000
169169
[NO_PID]: ecpg_process_output on line 21: OK: CREATE TABLE
170170
[NO_PID]: sqlca: code: 0, state: 00000
171-
[NO_PID]: ecpg_auto_prepare on line 23: statement found in cache; entry15328
171+
[NO_PID]: ecpg_auto_prepare on line 23: statement found in cache; entry15321
172172
[NO_PID]: sqlca: code: 0, state: 00000
173173
[NO_PID]: prepare_common on line 23: name ecpg1; query: "insert into T values ( 1 , null )"
174174
[NO_PID]: sqlca: code: 0, state: 00000
@@ -178,7 +178,7 @@
178178
[NO_PID]: sqlca: code: 0, state: 00000
179179
[NO_PID]: ecpg_process_output on line 23: OK: INSERT 0 1
180180
[NO_PID]: sqlca: code: 0, state: 00000
181-
[NO_PID]: ecpg_auto_prepare on line 24: statement found in cache; entry1640
181+
[NO_PID]: ecpg_auto_prepare on line 24: statement found in cache; entry1633
182182
[NO_PID]: sqlca: code: 0, state: 00000
183183
[NO_PID]: prepare_common on line 24: name ecpg2; query: "insert into T values ( 1 , $1 )"
184184
[NO_PID]: sqlca: code: 0, state: 00000
@@ -190,7 +190,7 @@
190190
[NO_PID]: sqlca: code: 0, state: 00000
191191
[NO_PID]: ecpg_process_output on line 24: OK: INSERT 0 1
192192
[NO_PID]: sqlca: code: 0, state: 00000
193-
[NO_PID]: ecpg_auto_prepare on line 26: statement found in cache; entry1640
193+
[NO_PID]: ecpg_auto_prepare on line 26: statement found in cache; entry1633
194194
[NO_PID]: sqlca: code: 0, state: 00000
195195
[NO_PID]: ecpg_execute on line 26: query: insert into T values ( 1 , $1 ); with 1 parameter(s) on connection ecpg1_regression
196196
[NO_PID]: sqlca: code: 0, state: 00000
@@ -208,7 +208,7 @@
208208
[NO_PID]: sqlca: code: 0, state: 00000
209209
[NO_PID]: ecpg_process_output on line 28: OK: INSERT 0 1
210210
[NO_PID]: sqlca: code: 0, state: 00000
211-
[NO_PID]: ecpg_auto_prepare on line 30: statement found in cache; entry13056
211+
[NO_PID]: ecpg_auto_prepare on line 30: statement found in cache; entry13049
212212
[NO_PID]: sqlca: code: 0, state: 00000
213213
[NO_PID]: prepare_common on line 30: name ecpg3; query: "select Item2 from T order by Item2 nulls last"
214214
[NO_PID]: sqlca: code: 0, state: 00000

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp