resource.go

// Copyright 2017 The Cockroach Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied. See the License for the specific language governing
// permissions and limitations under the License.

package mon

import "github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgerror"

// Resource is an interface used to abstract the specifics of tracking bytes
// usage by different types of resources.
type Resource interface {
	NewBudgetExceededError(requestedBytes int64, budgetBytes int64) error
}

// memoryResource is a Resource that represents memory.
type memoryResource struct{}

// MemoryResource is a utility singleton used as an argument when creating a
// BytesMonitor to indicate that the monitor will be tracking memory usage.
var MemoryResource Resource = memoryResource{}

// NewBudgetExceededError implements the Resource interface.
func (m memoryResource) NewBudgetExceededError(requestedBytes int64, budgetBytes int64) error {
	return pgerror.NewErrorf(
		pgerror.CodeOutOfMemoryError,
		"memory budget exceeded: %d bytes requested, %d bytes in budget",
		requestedBytes,
		budgetBytes,
	)
}

// diskResource is a Resource that represents disk.
type diskResource struct{}

// DiskResource is a utility singleton used as an argument when creating a
// BytesMonitor to indicate that the monitor will be tracking disk usage.
var DiskResource Resource = diskResource{}

// NewBudgetExceededError implements the Resource interface.
func (d diskResource) NewBudgetExceededError(requestedBytes int64, budgetBytes int64) error {
	return pgerror.NewErrorf(
		pgerror.CodeDiskFullError,
		"disk budget exceeded: %d bytes requested, %d bytes in budget",
		requestedBytes,
		budgetBytes,
	)
}