mirror of
https://github.com/jackc/pgx.git
synced 2025-05-31 11:42:24 +00:00
da9fc85c44
PreparedStatementDescription was too long. It also no longer entirely represents its purpose now that it is also intended for use with described statements.
53 lines
1.5 KiB
Go
53 lines
1.5 KiB
Go
// Package stmtcache is a cache that can be used to implement lazy prepared statements.
|
|
package stmtcache
|
|
|
|
import (
|
|
"context"
|
|
|
|
"github.com/jackc/pgconn"
|
|
)
|
|
|
|
const (
|
|
ModePrepare = iota // Cache should prepare named statements.
|
|
ModeDescribe // Cache should prepare the anonymous prepared statement to only fetch the description of the statement.
|
|
)
|
|
|
|
// Cache prepares and caches prepared statement descriptions.
|
|
type Cache interface {
|
|
// Get returns the prepared statement description for sql preparing or describing the sql on the server as needed.
|
|
Get(ctx context.Context, sql string) (*pgconn.StatementDescription, error)
|
|
|
|
// Clear removes all entries in the cache. Any prepared statements will be deallocated from the PostgreSQL session.
|
|
Clear(ctx context.Context) error
|
|
|
|
// Len returns the number of cached prepared statement descriptions.
|
|
Len() int
|
|
|
|
// Cap returns the maximum number of cached prepared statement descriptions.
|
|
Cap() int
|
|
|
|
// Mode returns the mode of the cache (ModePrepare or ModeDescribe)
|
|
Mode() int
|
|
}
|
|
|
|
// New returns the preferred cache implementation for mode and cap. mode is either ModePrepare or ModeDescribe. cap is
|
|
// the maximum size of the cache.
|
|
func New(conn *pgconn.PgConn, mode int, cap int) Cache {
|
|
mustBeValidMode(mode)
|
|
mustBeValidCap(cap)
|
|
|
|
return NewLRU(conn, mode, cap)
|
|
}
|
|
|
|
func mustBeValidMode(mode int) {
|
|
if mode != ModePrepare && mode != ModeDescribe {
|
|
panic("mode must be ModePrepare or ModeDescribe")
|
|
}
|
|
}
|
|
|
|
func mustBeValidCap(cap int) {
|
|
if cap < 1 {
|
|
panic("cache must have cap of >= 1")
|
|
}
|
|
}
|