Documentation
¶
Overview ¶
Usage ¶
The intern package allows users to intern string values.
Importantly the interners built using this package can take types which are _not_ strings but which can be used to generate strings. This has the advantage that when the string representation of an object has already been interned we can skip generating the string and just return the interned string.
An example where this would be advantageous would be in a system which converts a lot of integers to strings. If a lot of those integer values are common values then this package would avoid a lot of those string allocations.
The basic interface of an interner is a single method which looks like
someTypeInterner.Get(someTypeValue) string
The string value returned may be either a newly allocated string, or a previously allocated interned string from the cache. Interned strings are stored in an *offheap.Store. This means that there is no garbage collection cost associated with keeping large numbers of interned strings.
This package contains a number of pre-made interners for the types int64, float64, time.Time, []byte and string. But this package also includes the tools to build custom interners for other types.
Because the interned strings are manually managed, and we don't have a mechanism for knowing when to free interned string values, interned strings are retained for the life of the StringInterner instance. This means that we accumulate interned strings as the StringInterner is used. To prevent uncontrolled memory exhaustion we configure an upper limit on the total number of bytes which can be used to intern strings. When this limit is reached no new strings will be interned.
It is expected that strings which are a good target for interning should appear for interning frequently and there should be a finite number of these common string values. In the case where this pattern holds true a well configured StringIntern cache will intern these popular strings before the byte limit is reached. If strings to be interned evolve over time and don't have a stable set of common string values, then this interning approach will be less effective.
It should be reasonably easy to create new interners using the types found in the internbase package. Just following the implementation of the interners found in this package.
Index ¶
- type Interner
- func NewBytesInterner(config internbase.Config) Interner[[]byte]
- func NewFloat64Interner(config internbase.Config, fmt byte, prec, bitSize int) Interner[float64]
- func NewInt64Interner(config internbase.Config, base int) Interner[int64]
- func NewStringInterner(config internbase.Config) Interner[string]
- func NewTimeInterner(config internbase.Config, format string) Interner[time.Time]
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Interner ¶
type Interner[T any] interface { Get(t T) string GetStats() internbase.StatsSummary }
func NewBytesInterner ¶
func NewBytesInterner(config internbase.Config) Interner[[]byte]
func NewFloat64Interner ¶
func NewInt64Interner ¶
func NewInt64Interner(config internbase.Config, base int) Interner[int64]
func NewStringInterner ¶
func NewStringInterner(config internbase.Config) Interner[string]
Source Files
Directories