kvas

kvas is a minimal overhead key value store backed by the filesystem.

It comes with the following features:

• writes only happen for new data (verified with a SHA-256 hash);
• modifications are timestamped, allowing querying last modified by a timestamp;
• an in-memory index, allowing fast operations like confirming whether value set contains a key, enumerations;
• specific values in a set are stored individually as files;
• reductions - a slice of property values per key for fast in-memory operations like finding all keys that match specific value.
• list of reduction - a slice of reductions with additional fabric that establishes data relationships for transparent common operations (aliasing, joins).

Using kvas in your app

• Run go get github.com/boggydigital/kvas
• Import github.com/boggydigital/kvas
• For a key value set - connect to a local store with kvas.ConnectLocal(directory, extension)
  • Extensions supported: kvas.JsonExt (.json), kvas.GobExt (.gob)
• Use this key value set client to Get, Set, Cut values, as well as filter using CreatedAfter, ModifiedAfter, etc.

Key types provided by kvas

kvas comes with the following types:

• KeyValues - key value store backed by local filesystem
• ReduxValues - key reductions store (backed by kvas.KeyValues)
• ReduxAssets - collection of ReduxValues plus additional data relationship fabric

Example usage of kvas.KeyValues

NOTE: Error handling omitted for brevity.

lkv, _ := kvas.ConnectLocal(os.TempDir(), kvas.JsonExt)

key := "value1"
start := time.Now().Unix()

_ = lkv.Set(key, strings.NewReader(key))

if lkv.Has(key) {
    readCloser, _ := lkv.Get(key)
    defer readCloser.Close()
    // use readCloser to read data stored under "value1" key
}

fmt.Println(lkv.ModifiedAfter(start, false)) // prints: [value1]

Example usage of kvas.ReduxValues

NOTE: Error handling omitted for brevity.

rdx, _ := kvas.ConnectRedux(os.TempDir(), "titles")

for _, key := range rdx.Keys() {
    allKeyTitles, _ := rdx.GetAllValues(key)
    // process all titles for a key
}

// find all keys that have values containing "specific_title" (any case) 
matches := rdx.Match([]string{"specific_title"}, nil, true, true)

Example usage of kvas.ReduxAssets

NOTE: Error handling omitted for brevity.

rxa, _ := kvas.ConnectReduxAssets(os.TempDir(), nil, "titles", "country")

query := map[string][]string{
    "title": {"title1", "title2"},
    "country": {"states"},
}

// find all keys across "titles" and "countries" reductions that match query
matches := rxa.Match(query, true)