cache.go RawHistoryFolder

1package provider
2
3import (
4	"encoding/json"
5	"errors"
6	"os"
7	"path/filepath"
8	"time"
9)
10
11// ModelCache is the on-disk shape for discovered models.
12type ModelCache struct {
13	FetchedAt              time.Time         `json:"fetched_at"`
14	Models                 []Model           `json:"models"`
15	AuthoritativeProviders []string          `json:"authoritative_providers,omitempty"`
16	ProviderScopes         map[string]string `json:"provider_scopes,omitempty"`
17}
18
19// CacheTTL is how long a discovered list is considered fresh.
20const CacheTTL = 6 * time.Hour
21
22// LoadCache reads the model cache from path. Returns an empty ModelCache
23// (no error) if the file does not exist.
24func LoadCache(path string) (ModelCache, error) {
25	var c ModelCache
26	b, err := os.ReadFile(path)
27	if errors.Is(err, os.ErrNotExist) {
28		return c, nil
29	}
30	if err != nil {
31		return c, err
32	}
33	if err := json.Unmarshal(b, &c); err != nil {
34		return c, err
35	}
36	for i := range c.Models {
37		if c.Models[i].Source == "" {
38			c.Models[i].Source = "cache"
39		}
40	}
41	return c, nil
42}
43
44// SaveCache writes the cache atomically.
45func SaveCache(path string, c ModelCache) error {
46	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
47		return err
48	}
49	b, err := json.MarshalIndent(c, "", "  ")
50	if err != nil {
51		return err
52	}
53	tmp := path + ".tmp"
54	if err := os.WriteFile(tmp, b, 0o600); err != nil {
55		return err
56	}
57	return os.Rename(tmp, path)
58}
59
60// IsFresh reports whether the cache was fetched within CacheTTL.
61func (c ModelCache) IsFresh() bool {
62	if c.FetchedAt.IsZero() {
63		return false
64	}
65	return time.Since(c.FetchedAt) < CacheTTL
66}