wisski-cloud-distillery/internal/component/instances/wisski_prefix.go
2022-11-16 13:07:11 +01:00

150 lines
3.6 KiB
Go

package instances
import (
"bufio"
"path/filepath"
"strings"
"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
"github.com/tkw1536/goprogram/lib/collection"
_ "embed"
)
// NoPrefix checks if this WissKI instance is excluded from generating prefixes.
// TODO: Move this to the database!
func (wisski *WissKI) NoPrefix() bool {
return fsx.IsFile(wisski.instances.Environment, filepath.Join(wisski.FilesystemBase, "prefixes.skip"))
}
//go:embed php/list_uri_prefixes.php
var listURIPrefixesPHP string
// Prefixes returns the prefixes applying to this WissKI
//
// server is an optional server to fetch prefixes from.
// server may be nil.
func (wisski *WissKI) Prefixes(server *PHPServer) ([]string, error) {
prefixes, err := wisski.dbPrefixes(server)
if err != nil {
return nil, err
}
prefixes2, err := wisski.filePrefixes()
if err != nil {
return nil, err
}
return append(prefixes, prefixes2...), nil
}
func (wisski *WissKI) dbPrefixes(server *PHPServer) (prefixes []string, err error) {
// get all the ugly prefixes
err = wisski.ExecPHPScript(server, &prefixes, listURIPrefixesPHP, "list_prefixes")
if err != nil {
return nil, err
}
// filter out sequential prefixes
prefixes = collection.NonSequential(prefixes, func(prev, now string) bool {
return strings.HasPrefix(now, prev)
})
// load the list of blocked prefixes
blocks, err := wisski.instances.blockedPrefixes()
if err != nil {
return nil, err
}
// filter out blocked prefixes
return collection.Filter(prefixes, func(uri string) bool { return !hasAnyPrefix(uri, blocks) }), nil
}
func (instances *Instances) blockedPrefixes() ([]string, error) {
// open the resolver block file
file, err := instances.Environment.Open(instances.Config.SelfResolverBlockFile)
if err != nil {
return nil, err
}
var lines []string
// read all the lines that aren't a comment!
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
if line == "" || strings.HasPrefix(line, "//") || strings.HasPrefix(line, "#") {
continue
}
lines = append(lines, line)
}
// check if there was an error
if err := scanner.Err(); err != nil {
return nil, err
}
// and done!
return lines, nil
}
func hasAnyPrefix(candidate string, prefixes []string) bool {
return collection.Any(
prefixes,
func(prefix string) bool {
return strings.HasPrefix(candidate, prefix)
},
)
}
func (wisski *WissKI) filePrefixes() (prefixes []string, err error) {
path := filepath.Join(wisski.FilesystemBase, "prefixes")
if !fsx.IsFile(wisski.instances.Environment, path) {
return nil, nil
}
file, err := wisski.instances.Environment.Open(path)
if err != nil {
return nil, err
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
if len(line) == 0 || line[0] == '#' {
continue
}
prefixes = append(prefixes, line)
}
if scanner.Err() != nil {
return nil, scanner.Err()
}
return prefixes, nil
}
// CACHING
var PrefixConfigKey MetaKey = "prefix"
// Prefixes returns the cached prefixes from the given instance
func (wisski *WissKI) PrefixesCached() (results []string, err error) {
err = wisski.Metadata().GetAll(PrefixConfigKey, func(index, total int) any {
if results == nil {
results = make([]string, total)
}
return &results[index]
})
return
}
// UpdatePrefixes updates the cached prefixes of this instance
func (wisski *WissKI) UpdatePrefixes() error {
prefixes, err := wisski.Prefixes(nil)
if err != nil {
return err
}
return wisski.Metadata().SetAll(PrefixConfigKey, collection.AsAny(prefixes)...)
}