mirror of
https://github.com/NVIDIA/nvidia-container-toolkit
synced 2024-11-22 16:29:18 +00:00
55eb898186
This change allows the file Locator to be instantiated with multiple search prefixes. Signed-off-by: Evan Lezar <elezar@nvidia.com>
127 lines
4.0 KiB
Go
127 lines
4.0 KiB
Go
/*
|
|
# Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
|
|
#
|
|
# 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 lookup
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"path/filepath"
|
|
|
|
log "github.com/sirupsen/logrus"
|
|
)
|
|
|
|
// file can be used to locate file (or file-like elements) at a specified set of
|
|
// prefixes. The validity of a file is determined by a filter function.
|
|
type file struct {
|
|
logger *log.Logger
|
|
prefixes []string
|
|
filter func(string) error
|
|
}
|
|
|
|
// NewFileLocator creates a Locator that can be used to find files at the specified root.
|
|
// An optional list of prefixes can aslo be specified with each of these being searched in order.
|
|
// The specified root is prefixed to each of the prefixes to determine the final search path.
|
|
func NewFileLocator(logger *log.Logger, root string, prefixes ...string) Locator {
|
|
l := newFileLocator(logger, root, prefixes...)
|
|
|
|
return &l
|
|
}
|
|
|
|
func newFileLocator(logger *log.Logger, root string, prefixes ...string) file {
|
|
|
|
return file{
|
|
logger: logger,
|
|
prefixes: getSearchPrefixes(root, prefixes...),
|
|
filter: assertFile,
|
|
}
|
|
}
|
|
|
|
// getSearchPrefixes generates a list of unique paths to be searched by a file locator.
|
|
//
|
|
// For each of the unique prefixes <p> specified the path <root><p> is searched, where <root> is the
|
|
// specified root. If no prefixes are specified, <root> is returned as the only search prefix.
|
|
//
|
|
// Note that an empty root is equivalent to searching relative to the current working directory, and
|
|
// if the root filesystem should be searched instead, root should be specified as "/" explicitly.
|
|
//
|
|
// Also, a prefix of "" forces the root to be included in returned set of paths. This means that if
|
|
// the root in addition to another prefix must be searched the function should be called with:
|
|
//
|
|
// getSearchPrefixes("/root", "", "another/path")
|
|
//
|
|
// and will result in the search paths []{"/root", "/root/another/path"} being returned.
|
|
func getSearchPrefixes(root string, prefixes ...string) []string {
|
|
seen := make(map[string]bool)
|
|
var uniquePrefixes []string
|
|
for _, p := range prefixes {
|
|
if seen[p] {
|
|
continue
|
|
}
|
|
seen[p] = true
|
|
uniquePrefixes = append(uniquePrefixes, filepath.Join(root, p))
|
|
}
|
|
|
|
if len(uniquePrefixes) == 0 {
|
|
uniquePrefixes = append(uniquePrefixes, root)
|
|
}
|
|
|
|
return uniquePrefixes
|
|
}
|
|
|
|
var _ Locator = (*file)(nil)
|
|
|
|
// Locate attempts to find files with names matching the specified pattern.
|
|
// All prefixes are searched and any matching candidates are returned. If no matches are found, an error is returned.
|
|
func (p file) Locate(pattern string) ([]string, error) {
|
|
var filenames []string
|
|
for _, prefix := range p.prefixes {
|
|
pathPattern := filepath.Join(prefix, pattern)
|
|
candidates, err := filepath.Glob(pathPattern)
|
|
if err != nil {
|
|
p.logger.Debugf("Checking pattern '%v' failed: %v", pathPattern, err)
|
|
}
|
|
|
|
for _, candidate := range candidates {
|
|
p.logger.Debugf("Checking candidate '%v'", candidate)
|
|
err := p.filter(candidate)
|
|
if err != nil {
|
|
p.logger.Debugf("Candidate '%v' does not meet requirements: %v", candidate, err)
|
|
continue
|
|
}
|
|
filenames = append(filenames, candidate)
|
|
}
|
|
}
|
|
if len(filenames) == 0 {
|
|
return nil, fmt.Errorf("pattern %v not found", pattern)
|
|
}
|
|
return filenames, nil
|
|
}
|
|
|
|
// assertFile checks whether the specified path is a regular file
|
|
func assertFile(filename string) error {
|
|
info, err := os.Stat(filename)
|
|
if err != nil {
|
|
return fmt.Errorf("error getting info for %v: %v", filename, err)
|
|
}
|
|
|
|
if info.IsDir() {
|
|
return fmt.Errorf("specified path '%v' is a directory", filename)
|
|
}
|
|
|
|
return nil
|
|
}
|