Fossil SCM

***FIXME TEST*** - do not commit to trunk ***FIXME TEST*** Make the total size and total number of entries in the content cache optionally set from an environent variable. This is for testing so we can get an idea of optimal numbers, however, the cache needs to be redesigned so this is (a) a short-term minimally intrusive performance fix and (b) experimentation to help with a resdesign.

danshearer 2026-08-22 06:48 UTC cache-speedups

Commit 8424663f26d776be41a2bde44f5acd32db3f4a6a451fc1ef98a30c7d6e0d125e

Parent bce3a5a5d4ac2f4…

1 file changed +31 -2

~ src/content.c

M src/content.c

+31 -2

		--- src/content.c
		+++ src/content.c
		@@ -22,10 +22,13 @@
22	22	#include <assert.h>
23	23
24	24	/*
25	25	** The artifact retrieval cache
26	26	*/
	27	+static int cacheMaxN = 0; /* Max cache entries */
	28	+static i64 cacheMaxSz = 0; /* Max cache bytes */
	29	+
27	30	static struct {
28	31	i64 szTotal; /* Total size of all entries in the cache */
29	32	int n; /* Current number of cache entries */
30	33	int nAlloc; /* Number of slots allocated in a[] */
31	34	int nextAge; /* Age counter for implementing LRU */
		@@ -77,16 +80,42 @@
77	80	** This routines hands responsibility for the artifact over to the cache.
78	81	** The cache will deallocate memory when it has finished with it.
79	82	*/
80	83	void content_cache_insert(int rid, Blob *pBlob){
81	84	struct cacheLine *p;
82		- if( contentCache.n>500 \|\| contentCache.szTotal>50000000 ){
	85	+
	86	+ if( cacheMaxN==0 ){ /* FIXME TEST Not to be merged to trunk FIXME */
	87	+ const char *z;
	88	+
	89	+ cacheMaxN = 500; /* old hardcoded value */
	90	+ z = getenv("FOSSIL_CACHE_N");
	91	+ if( z!=0 ){
	92	+ int val = atoi(z);
	93	+ if( val>0 ) cacheMaxN = val;
	94	+ }
	95	+
	96	+ cacheMaxSz = (i64)50000000; /old hardcoded value /
	97	+ z = getenv("FOSSIL_CACHE_SZ");
	98	+ if( z!=0 ){
	99	+ i64 val = (i64)atoll(z);
	100	+ if( val>0 ) cacheMaxSz = val;
	101	+ }
	102	+ }
	103	+
	104	+ if( cacheMaxN==0 ){
	105	+ const char *z;
	106	+ z = getenv("FOSSIL_CACHE_N");
	107	+ cacheMaxN = (z!=0 && atoi(z)>0) ? atoi(z) : 500;
	108	+ z = getenv("FOSSIL_CACHE_SZ");
	109	+ cacheMaxSz = (z!=0 && atoll(z)>0) ? (i64)atoll(z) : (i64)50000000;
	110	+ }
	111	+ if( contentCache.n>cacheMaxN \|\| contentCache.szTotal>cacheMaxSz ){
83	112	i64 szBefore;
84	113	do{
85	114	szBefore = contentCache.szTotal;
86	115	content_cache_expire_oldest();
87		- }while( contentCache.szTotal>50000000 && contentCache.szTotal<szBefore );
	116	+ }while( contentCache.szTotal>cacheMaxSz && contentCache.szTotal<szBefore );
88	117	}
89	118	if( contentCache.n>=contentCache.nAlloc ){
90	119	contentCache.nAlloc = contentCache.nAlloc*2 + 10;
91	120	contentCache.a = fossil_realloc(contentCache.a,
92	121	contentCache.nAlloc*sizeof(contentCache.a[0]));
93	122

	--- src/content.c
	+++ src/content.c
	@@ -22,10 +22,13 @@
22	#include <assert.h>
23
24	/*
25	** The artifact retrieval cache
26	*/



27	static struct {
28	i64 szTotal; /* Total size of all entries in the cache */
29	int n; /* Current number of cache entries */
30	int nAlloc; /* Number of slots allocated in a[] */
31	int nextAge; /* Age counter for implementing LRU */
	@@ -77,16 +80,42 @@
77	** This routines hands responsibility for the artifact over to the cache.
78	** The cache will deallocate memory when it has finished with it.
79	*/
80	void content_cache_insert(int rid, Blob *pBlob){
81	struct cacheLine *p;
82	if( contentCache.n>500 \|\| contentCache.szTotal>50000000 ){


























83	i64 szBefore;
84	do{
85	szBefore = contentCache.szTotal;
86	content_cache_expire_oldest();
87	}while( contentCache.szTotal>50000000 && contentCache.szTotal<szBefore );
88	}
89	if( contentCache.n>=contentCache.nAlloc ){
90	contentCache.nAlloc = contentCache.nAlloc*2 + 10;
91	contentCache.a = fossil_realloc(contentCache.a,
92	contentCache.nAlloc*sizeof(contentCache.a[0]));
93

	--- src/content.c
	+++ src/content.c
	@@ -22,10 +22,13 @@
22	#include <assert.h>
23
24	/*
25	** The artifact retrieval cache
26	*/
27	static int cacheMaxN = 0; /* Max cache entries */
28	static i64 cacheMaxSz = 0; /* Max cache bytes */
29
30	static struct {
31	i64 szTotal; /* Total size of all entries in the cache */
32	int n; /* Current number of cache entries */
33	int nAlloc; /* Number of slots allocated in a[] */
34	int nextAge; /* Age counter for implementing LRU */
	@@ -77,16 +80,42 @@
80	** This routines hands responsibility for the artifact over to the cache.
81	** The cache will deallocate memory when it has finished with it.
82	*/
83	void content_cache_insert(int rid, Blob *pBlob){
84	struct cacheLine *p;
85
86	if( cacheMaxN==0 ){ /* FIXME TEST Not to be merged to trunk FIXME */
87	const char *z;
88
89	cacheMaxN = 500; /* old hardcoded value */
90	z = getenv("FOSSIL_CACHE_N");
91	if( z!=0 ){
92	int val = atoi(z);
93	if( val>0 ) cacheMaxN = val;
94	}
95
96	cacheMaxSz = (i64)50000000; /old hardcoded value /
97	z = getenv("FOSSIL_CACHE_SZ");
98	if( z!=0 ){
99	i64 val = (i64)atoll(z);
100	if( val>0 ) cacheMaxSz = val;
101	}
102	}
103
104	if( cacheMaxN==0 ){
105	const char *z;
106	z = getenv("FOSSIL_CACHE_N");
107	cacheMaxN = (z!=0 && atoi(z)>0) ? atoi(z) : 500;
108	z = getenv("FOSSIL_CACHE_SZ");
109	cacheMaxSz = (z!=0 && atoll(z)>0) ? (i64)atoll(z) : (i64)50000000;
110	}
111	if( contentCache.n>cacheMaxN \|\| contentCache.szTotal>cacheMaxSz ){
112	i64 szBefore;
113	do{
114	szBefore = contentCache.szTotal;
115	content_cache_expire_oldest();
116	}while( contentCache.szTotal>cacheMaxSz && contentCache.szTotal<szBefore );
117	}
118	if( contentCache.n>=contentCache.nAlloc ){
119	contentCache.nAlloc = contentCache.nAlloc*2 + 10;
120	contentCache.a = fossil_realloc(contentCache.a,
121	contentCache.nAlloc*sizeof(contentCache.a[0]));
122

Fossil SCM

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