Add a consolidated file cache

This commits reworks how file caching is performed in Hugo. Now there is only one way, and it can be configured.

This is the default configuration:

```toml
[caches]
[caches.getjson]
dir = ":cacheDir"
maxAge = -1
[caches.getcsv]
dir = ":cacheDir"
maxAge = -1
[caches.images]
dir = ":resourceDir/_gen"
maxAge = -1
[caches.assets]
dir = ":resourceDir/_gen"
maxAge = -1
```

You can override any of these cache setting in your own `config.toml`.

The placeholders explained:

`:cacheDir`: This is the value of the `cacheDir` config option if set (can also be set via OS env variable `HUGO_CACHEDIR`). It will fall back to `/opt/build/cache/hugo_cache/` on Netlify, or a `hugo_cache` directory below the OS temp dir for the others.
`:resourceDir`: This is the value of the `resourceDir` config option.

`maxAge` is the time in seconds before a cache entry will be evicted, -1 means forever and 0 effectively turns that particular cache off.

This means that if you run your builds on Netlify, all caches configured with `:cacheDir` will be saved and restored on the next build. For other CI vendors, please read their documentation. For an CircleCI example, see https://github.com/bep/hugo-sass-test/blob/6c3960a8f4b90e8938228688bc49bdcdd6b2d99e/.circleci/config.yml

Fixes #5404

2 files changed, 0 insertions, 11 deletions

diff --git a/hugolib/filesystems/basefs.go b/hugolib/filesystems/basefs.go
index ee1c870d9..8fc1861b8 100644
--- a/hugolib/filesystems/basefs.go
+++ b/hugolib/filesystems/basefs.go
@@ -81,7 +81,6 @@ type SourceFilesystems struct {
 	Layouts    *SourceFilesystem
 	Archetypes *SourceFilesystem
 	Assets     *SourceFilesystem
-	Resources  *SourceFilesystem
 
 	// This is a unified read-only view of the project's and themes' workdir.
 	Work *SourceFilesystem
@@ -376,13 +375,6 @@ func (b *sourceFilesystemsBuilder) Build() (*SourceFilesystems, error) {
 	}
 	b.result.Assets = sfs
 
-	sfs, err = b.createFs(true, false, "resourceDir", "resources")
-	if err != nil {
-		return nil, err
-	}
-
-	b.result.Resources = sfs
-
 	sfs, err = b.createFs(false, true, "", "")
 	if err != nil {
 		return nil, err
diff --git a/hugolib/filesystems/basefs_test.go b/hugolib/filesystems/basefs_test.go
index ec6ccb30c..8e9b7235c 100644
--- a/hugolib/filesystems/basefs_test.go
+++ b/hugolib/filesystems/basefs_test.go
@@ -108,7 +108,6 @@ theme = ["atheme"]
 	checkFileCount(bfs.Data.Fs, "", assert, 9)        // 7 + 2 themes
 	checkFileCount(bfs.Archetypes.Fs, "", assert, 10) // 8 + 2 themes
 	checkFileCount(bfs.Assets.Fs, "", assert, 9)
-	checkFileCount(bfs.Resources.Fs, "", assert, 10)
 	checkFileCount(bfs.Work.Fs, "", assert, 78)
 
 	assert.Equal([]string{filepath.FromSlash("/my/work/mydata"), filepath.FromSlash("/my/work/themes/btheme/data"), filepath.FromSlash("/my/work/themes/atheme/data")}, bfs.Data.Dirnames)
@@ -229,8 +228,6 @@ func TestRealDirs(t *testing.T) {
 	assert.Equal(filepath.Join(root, "myassets/scss"), realDirs[0])
 	assert.Equal(filepath.Join(themesDir, "mytheme/assets/scss"), realDirs[len(realDirs)-1])
 
-	checkFileCount(bfs.Resources.Fs, "", assert, 3)
-
 	assert.NotNil(bfs.themeFs)
 	fi, b, err := bfs.themeFs.(afero.Lstater).LstatIfPossible(filepath.Join("resources", "t1.txt"))
 	assert.NoError(err)