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	Version                int               `json:"version,omitempty"`
14	FetchedAt              time.Time         `json:"fetched_at"`
15	Models                 []Model           `json:"models"`
16	AuthoritativeProviders []string          `json:"authoritative_providers,omitempty"`
17	ProviderScopes         map[string]string `json:"provider_scopes,omitempty"`
18}
19
20// ModelCacheVersion invalidates caches created before OpenCode Go protocol
21// routing was based on models.dev adapters. Older caches must not be loaded as
22// routing metadata because they can silently select the wrong wire protocol.
23const ModelCacheVersion = 4
24
25// CacheTTL is how long a discovered list is considered fresh. Model metadata
26// and availability change less often than a typical process starts, so keep
27// the synchronized catalog for one day before querying its sources again.
28const CacheTTL = 24 * time.Hour
29
30// LoadCache reads the model cache from path. Returns an empty ModelCache
31// (no error) if the file does not exist.
32func LoadCache(path string) (ModelCache, error) {
33	var c ModelCache
34	b, err := os.ReadFile(path)
35	if errors.Is(err, os.ErrNotExist) {
36		return c, nil
37	}
38	if err != nil {
39		return c, err
40	}
41	if err := json.Unmarshal(b, &c); err != nil {
42		return c, err
43	}
44	for i := range c.Models {
45		if c.Models[i].Source == "" {
46			c.Models[i].Source = "cache"
47		}
48	}
49	return c, nil
50}
51
52// SaveCache writes the cache atomically.
53func SaveCache(path string, c ModelCache) error {
54	if c.Version == 0 {
55		c.Version = ModelCacheVersion
56	}
57	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
58		return err
59	}
60	b, err := json.MarshalIndent(c, "", "  ")
61	if err != nil {
62		return err
63	}
64	tmp := path + ".tmp"
65	if err := os.WriteFile(tmp, b, 0o600); err != nil {
66		return err
67	}
68	return os.Rename(tmp, path)
69}
70
71// IsFresh reports whether the current-format cache was fetched within CacheTTL.
72func (c ModelCache) IsFresh() bool {
73	if c.Version != ModelCacheVersion || c.FetchedAt.IsZero() {
74		return false
75	}
76	return time.Since(c.FetchedAt) < CacheTTL
77}