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}
16
17// CacheTTL is how long a discovered list is considered fresh.
18const CacheTTL = 6 * time.Hour
19
20// LoadCache reads the model cache from path. Returns an empty ModelCache
21// (no error) if the file does not exist.
22func LoadCache(path string) (ModelCache, error) {
23	var c ModelCache
24	b, err := os.ReadFile(path)
25	if errors.Is(err, os.ErrNotExist) {
26		return c, nil
27	}
28	if err != nil {
29		return c, err
30	}
31	if err := json.Unmarshal(b, &c); err != nil {
32		return c, err
33	}
34	for i := range c.Models {
35		if c.Models[i].Source == "" {
36			c.Models[i].Source = "cache"
37		}
38	}
39	return c, nil
40}
41
42// SaveCache writes the cache atomically.
43func SaveCache(path string, c ModelCache) error {
44	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
45		return err
46	}
47	b, err := json.MarshalIndent(c, "", "  ")
48	if err != nil {
49		return err
50	}
51	tmp := path + ".tmp"
52	if err := os.WriteFile(tmp, b, 0o644); err != nil {
53		return err
54	}
55	return os.Rename(tmp, path)
56}
57
58// IsFresh reports whether the cache was fetched within CacheTTL.
59func (c ModelCache) IsFresh() bool {
60	if c.FetchedAt.IsZero() {
61		return false
62	}
63	return time.Since(c.FetchedAt) < CacheTTL
64}