frostfs-node/pkg/services/container/announcement/load/controller/deps.go

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package loadcontroller
import (
"context"
"io"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
)
// UsedSpaceHandler describes the signature of the container.SizeEstimation
// value handling function.
//
// Termination of processing without failures is usually signaled
// with a zero error, while a specific value may describe the reason
// for failure.
type UsedSpaceHandler func(container.SizeEstimation) error
// UsedSpaceFilter describes the signature of the function for
// checking whether a value meets a certain criterion.
//
// Return of true means conformity, false - vice versa.
type UsedSpaceFilter func(container.SizeEstimation) bool
// Iterator is a group of methods provided by entity
// which can iterate over a group of container.SizeEstimation values.
type Iterator interface {
// Iterate must start an iterator over values that
// meet the filter criterion (returns true).
// For each such value should call a handler, the error
// of which should be directly returned from the method.
//
// Internal failures of the iterator are also signaled via
// an error. After a successful call to the last value
// handler, nil should be returned.
Iterate(UsedSpaceFilter, UsedSpaceHandler) error
}
// IteratorProvider is a group of methods provided
// by entity which generates iterators over
// container.SizeEstimation values.
type IteratorProvider interface {
// InitIterator should return an initialized Iterator.
//
// Initialization problems are reported via error.
// If no error was returned, then the Iterator must not be nil.
//
// Implementations can have different logic for different
// contexts, so specific ones may document their own behavior.
InitIterator(context.Context) (Iterator, error)
}
// Writer describes the interface for storing container.SizeEstimation values.
//
// This interface is provided by both local storage
// of values and remote (wrappers over the RPC).
type Writer interface {
// Put performs a write operation of container.SizeEstimation value
// and returns any error encountered.
//
// All values after the Close call must be flushed to the
// physical target. Implementations can cache values before
// Close operation.
//
// Put must not be called after Close.
Put(container.SizeEstimation) error
// Close exits with method-providing Writer.
//
// All cached values must be flushed before
// the Close's return.
//
// Methods must not be called after Close.
io.Closer
}
// WriterProvider is a group of methods provided
// by entity which generates keepers of
// container.SizeEstimation values.
type WriterProvider interface {
// InitWriter should return an initialized Writer.
//
// Initialization problems are reported via error.
// If no error was returned, then the Writer must not be nil.
//
// Implementations can have different logic for different
// contexts, so specific ones may document their own behavior.
InitWriter(context.Context) (Writer, error)
}