unlimited_cache.go

Documentation: github.com/jackc/pgx/v5/internal/stmtcache

     1  package stmtcache
     2  
     3  import (
     4  	"math"
     5  
     6  	"github.com/jackc/pgx/v5/pgconn"
     7  )
     8  
     9  // UnlimitedCache implements Cache with no capacity limit.
    10  type UnlimitedCache struct {
    11  	m            map[string]*pgconn.StatementDescription
    12  	invalidStmts []*pgconn.StatementDescription
    13  }
    14  
    15  // NewUnlimitedCache creates a new UnlimitedCache.
    16  func NewUnlimitedCache() *UnlimitedCache {
    17  	return &UnlimitedCache{
    18  		m: make(map[string]*pgconn.StatementDescription),
    19  	}
    20  }
    21  
    22  // Get returns the statement description for sql. Returns nil if not found.
    23  func (c *UnlimitedCache) Get(sql string) *pgconn.StatementDescription {
    24  	return c.m[sql]
    25  }
    26  
    27  // Put stores sd in the cache. Put panics if sd.SQL is "". Put does nothing if sd.SQL already exists in the cache.
    28  func (c *UnlimitedCache) Put(sd *pgconn.StatementDescription) {
    29  	if sd.SQL == "" {
    30  		panic("cannot store statement description with empty SQL")
    31  	}
    32  
    33  	if _, present := c.m[sd.SQL]; present {
    34  		return
    35  	}
    36  
    37  	c.m[sd.SQL] = sd
    38  }
    39  
    40  // Invalidate invalidates statement description identified by sql. Does nothing if not found.
    41  func (c *UnlimitedCache) Invalidate(sql string) {
    42  	if sd, ok := c.m[sql]; ok {
    43  		delete(c.m, sql)
    44  		c.invalidStmts = append(c.invalidStmts, sd)
    45  	}
    46  }
    47  
    48  // InvalidateAll invalidates all statement descriptions.
    49  func (c *UnlimitedCache) InvalidateAll() {
    50  	for _, sd := range c.m {
    51  		c.invalidStmts = append(c.invalidStmts, sd)
    52  	}
    53  
    54  	c.m = make(map[string]*pgconn.StatementDescription)
    55  }
    56  
    57  // GetInvalidated returns a slice of all statement descriptions invalidated since the last call to RemoveInvalidated.
    58  func (c *UnlimitedCache) GetInvalidated() []*pgconn.StatementDescription {
    59  	return c.invalidStmts
    60  }
    61  
    62  // RemoveInvalidated removes all invalidated statement descriptions. No other calls to Cache must be made between a
    63  // call to GetInvalidated and RemoveInvalidated or RemoveInvalidated may remove statement descriptions that were
    64  // never seen by the call to GetInvalidated.
    65  func (c *UnlimitedCache) RemoveInvalidated() {
    66  	c.invalidStmts = nil
    67  }
    68  
    69  // Len returns the number of cached prepared statement descriptions.
    70  func (c *UnlimitedCache) Len() int {
    71  	return len(c.m)
    72  }
    73  
    74  // Cap returns the maximum number of cached prepared statement descriptions.
    75  func (c *UnlimitedCache) Cap() int {
    76  	return math.MaxInt
    77  }
    78
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