From 6ea4d2c82de80efc87708e5e182034b7c6c2019e Mon Sep 17 00:00:00 2001 From: Gibheer Date: Thu, 5 Sep 2024 19:38:25 +0200 Subject: switch from github.com/lib/pq to github.com/jackc/pgx/v5 lib/pq is out of maintenance for some time now, so switch to the newer more active library. Looks like it finally stabilized after a long time. --- .../jackc/pgx/v5/internal/stmtcache/lru_cache.go | 112 +++++++++++++++++++++ .../jackc/pgx/v5/internal/stmtcache/stmtcache.go | 45 +++++++++ .../pgx/v5/internal/stmtcache/unlimited_cache.go | 77 ++++++++++++++ 3 files changed, 234 insertions(+) create mode 100644 vendor/github.com/jackc/pgx/v5/internal/stmtcache/lru_cache.go create mode 100644 vendor/github.com/jackc/pgx/v5/internal/stmtcache/stmtcache.go create mode 100644 vendor/github.com/jackc/pgx/v5/internal/stmtcache/unlimited_cache.go (limited to 'vendor/github.com/jackc/pgx/v5/internal/stmtcache') diff --git a/vendor/github.com/jackc/pgx/v5/internal/stmtcache/lru_cache.go b/vendor/github.com/jackc/pgx/v5/internal/stmtcache/lru_cache.go new file mode 100644 index 0000000..dec83f4 --- /dev/null +++ b/vendor/github.com/jackc/pgx/v5/internal/stmtcache/lru_cache.go @@ -0,0 +1,112 @@ +package stmtcache + +import ( + "container/list" + + "github.com/jackc/pgx/v5/pgconn" +) + +// LRUCache implements Cache with a Least Recently Used (LRU) cache. +type LRUCache struct { + cap int + m map[string]*list.Element + l *list.List + invalidStmts []*pgconn.StatementDescription +} + +// NewLRUCache creates a new LRUCache. cap is the maximum size of the cache. +func NewLRUCache(cap int) *LRUCache { + return &LRUCache{ + cap: cap, + m: make(map[string]*list.Element), + l: list.New(), + } +} + +// Get returns the statement description for sql. Returns nil if not found. +func (c *LRUCache) Get(key string) *pgconn.StatementDescription { + if el, ok := c.m[key]; ok { + c.l.MoveToFront(el) + return el.Value.(*pgconn.StatementDescription) + } + + return nil + +} + +// 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") + } + + if _, present := c.m[sd.SQL]; present { + 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() + } + + el := c.l.PushFront(sd) + c.m[sd.SQL] = el +} + +// Invalidate invalidates statement description identified by sql. Does nothing if not found. +func (c *LRUCache) Invalidate(sql string) { + if el, ok := c.m[sql]; ok { + delete(c.m, sql) + c.invalidStmts = append(c.invalidStmts, el.Value.(*pgconn.StatementDescription)) + c.l.Remove(el) + } +} + +// InvalidateAll invalidates all statement descriptions. +func (c *LRUCache) InvalidateAll() { + el := c.l.Front() + for el != nil { + c.invalidStmts = append(c.invalidStmts, el.Value.(*pgconn.StatementDescription)) + el = el.Next() + } + + c.m = make(map[string]*list.Element) + c.l = list.New() +} + +// GetInvalidated returns a slice of all statement descriptions invalidated since the last call to RemoveInvalidated. +func (c *LRUCache) GetInvalidated() []*pgconn.StatementDescription { + return c.invalidStmts +} + +// RemoveInvalidated removes all invalidated statement descriptions. No other calls to Cache must be made between a +// call to GetInvalidated and RemoveInvalidated or RemoveInvalidated may remove statement descriptions that were +// never seen by the call to GetInvalidated. +func (c *LRUCache) RemoveInvalidated() { + c.invalidStmts = nil +} + +// Len returns the number of cached prepared statement descriptions. +func (c *LRUCache) Len() int { + return c.l.Len() +} + +// Cap returns the maximum number of cached prepared statement descriptions. +func (c *LRUCache) Cap() int { + return c.cap +} + +func (c *LRUCache) invalidateOldest() { + oldest := c.l.Back() + sd := oldest.Value.(*pgconn.StatementDescription) + c.invalidStmts = append(c.invalidStmts, sd) + delete(c.m, sd.SQL) + c.l.Remove(oldest) +} diff --git a/vendor/github.com/jackc/pgx/v5/internal/stmtcache/stmtcache.go b/vendor/github.com/jackc/pgx/v5/internal/stmtcache/stmtcache.go new file mode 100644 index 0000000..d57bdd2 --- /dev/null +++ b/vendor/github.com/jackc/pgx/v5/internal/stmtcache/stmtcache.go @@ -0,0 +1,45 @@ +// Package stmtcache is a cache for statement descriptions. +package stmtcache + +import ( + "crypto/sha256" + "encoding/hex" + + "github.com/jackc/pgx/v5/pgconn" +) + +// StatementName returns a statement name that will be stable for sql across multiple connections and program +// executions. +func StatementName(sql string) string { + digest := sha256.Sum256([]byte(sql)) + return "stmtcache_" + hex.EncodeToString(digest[0:24]) +} + +// Cache caches statement descriptions. +type Cache interface { + // Get returns the statement description for sql. Returns nil if not found. + Get(sql 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(sd *pgconn.StatementDescription) + + // Invalidate invalidates statement description identified by sql. Does nothing if not found. + Invalidate(sql string) + + // InvalidateAll invalidates all statement descriptions. + InvalidateAll() + + // GetInvalidated returns a slice of all statement descriptions invalidated since the last call to RemoveInvalidated. + GetInvalidated() []*pgconn.StatementDescription + + // RemoveInvalidated removes all invalidated statement descriptions. No other calls to Cache must be made between a + // call to GetInvalidated and RemoveInvalidated or RemoveInvalidated may remove statement descriptions that were + // never seen by the call to GetInvalidated. + RemoveInvalidated() + + // Len returns the number of cached prepared statement descriptions. + Len() int + + // Cap returns the maximum number of cached prepared statement descriptions. + Cap() int +} diff --git a/vendor/github.com/jackc/pgx/v5/internal/stmtcache/unlimited_cache.go b/vendor/github.com/jackc/pgx/v5/internal/stmtcache/unlimited_cache.go new file mode 100644 index 0000000..6964132 --- /dev/null +++ b/vendor/github.com/jackc/pgx/v5/internal/stmtcache/unlimited_cache.go @@ -0,0 +1,77 @@ +package stmtcache + +import ( + "math" + + "github.com/jackc/pgx/v5/pgconn" +) + +// UnlimitedCache implements Cache with no capacity limit. +type UnlimitedCache struct { + m map[string]*pgconn.StatementDescription + invalidStmts []*pgconn.StatementDescription +} + +// NewUnlimitedCache creates a new UnlimitedCache. +func NewUnlimitedCache() *UnlimitedCache { + return &UnlimitedCache{ + m: make(map[string]*pgconn.StatementDescription), + } +} + +// Get returns the statement description for sql. Returns nil if not found. +func (c *UnlimitedCache) Get(sql string) *pgconn.StatementDescription { + return c.m[sql] +} + +// Put stores sd in the cache. Put panics if sd.SQL is "". Put does nothing if sd.SQL already exists in the cache. +func (c *UnlimitedCache) Put(sd *pgconn.StatementDescription) { + if sd.SQL == "" { + panic("cannot store statement description with empty SQL") + } + + if _, present := c.m[sd.SQL]; present { + return + } + + c.m[sd.SQL] = sd +} + +// Invalidate invalidates statement description identified by sql. Does nothing if not found. +func (c *UnlimitedCache) Invalidate(sql string) { + if sd, ok := c.m[sql]; ok { + delete(c.m, sql) + c.invalidStmts = append(c.invalidStmts, sd) + } +} + +// InvalidateAll invalidates all statement descriptions. +func (c *UnlimitedCache) InvalidateAll() { + for _, sd := range c.m { + c.invalidStmts = append(c.invalidStmts, sd) + } + + c.m = make(map[string]*pgconn.StatementDescription) +} + +// GetInvalidated returns a slice of all statement descriptions invalidated since the last call to RemoveInvalidated. +func (c *UnlimitedCache) GetInvalidated() []*pgconn.StatementDescription { + return c.invalidStmts +} + +// RemoveInvalidated removes all invalidated statement descriptions. No other calls to Cache must be made between a +// call to GetInvalidated and RemoveInvalidated or RemoveInvalidated may remove statement descriptions that were +// never seen by the call to GetInvalidated. +func (c *UnlimitedCache) RemoveInvalidated() { + c.invalidStmts = nil +} + +// Len returns the number of cached prepared statement descriptions. +func (c *UnlimitedCache) Len() int { + return len(c.m) +} + +// Cap returns the maximum number of cached prepared statement descriptions. +func (c *UnlimitedCache) Cap() int { + return math.MaxInt +} -- cgit v1.2.3-70-g09d2