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stmtcache: Use deterministic, stable statement names

Statement names are now a function of the SQL. This may make database
diagnostics, monitoring, and profiling easier.
This commit is contained in:
Jack Christensen
2023-09-23 09:55:05 -05:00
parent bbe2653bc5
commit 7de53a958b
3 changed files with 21 additions and 12 deletions
+11 -1
View File
@@ -34,7 +34,8 @@ func (c *LRUCache) Get(key string) *pgconn.StatementDescription {
}
// Put stores sd in the cache. Put panics if sd.SQL is "". Put does nothing if sd.SQL already exists in the cache.
// Put stores sd in the cache. Put panics if sd.SQL is "". Put does nothing if sd.SQL already exists in the cache or
// sd.SQL has been invalidated and HandleInvalidated has not been called yet.
func (c *LRUCache) Put(sd *pgconn.StatementDescription) {
if sd.SQL == "" {
panic("cannot store statement description with empty SQL")
@@ -44,6 +45,13 @@ func (c *LRUCache) Put(sd *pgconn.StatementDescription) {
return
}
// The statement may have been invalidated but not yet handled. Do not readd it to the cache.
for _, invalidSD := range c.invalidStmts {
if invalidSD.SQL == sd.SQL {
return
}
}
if c.l.Len() == c.cap {
c.invalidateOldest()
}
@@ -73,6 +81,8 @@ func (c *LRUCache) InvalidateAll() {
c.l = list.New()
}
// HandleInvalidated returns a slice of all statement descriptions invalidated since the last call to HandleInvalidated.
// Typically, the caller will then deallocate them.
func (c *LRUCache) HandleInvalidated() []*pgconn.StatementDescription {
invalidStmts := c.invalidStmts
c.invalidStmts = nil