import

pmkeyvdb/keyvdb.go

@@ -0,0 +1,161 @@
+//
+package pmkeyvdb
+
+import (
+    "bytes"
+    "errors"
+    "fmt"
+    "github.com/syndtr/goleveldb/leveldb"
+)
+
+type DB struct {
+    db *leveldb.DB
+}
+
+func NewDB() *DB {
+    return &DB{}
+}
+
+func (this *DB) Open(filename string) error {
+    var err error
+    if this.db != nil {
+        this.Close()
+    }
+    db, err := leveldb.OpenFile(filename, nil)
+    if err != nil {
+         return errors.New(fmt.Sprintf("cannot open database: %v", err))
+    }
+    this.db = db
+    return err
+}
+
+func (this *DB) Set(key []byte, value []byte) error {
+    var err error
+    err = this.db.Put(key, value, nil)
+    if err != nil {
+        return errors.New("db not yet open")
+
+        return err
+    }
+    return err
+}
+
+func (this *DB) Get(key []byte) ([]byte, error) {
+    var err   error
+    var value []byte
+    value, err = this.db.Get(key, nil)
+    if err != nil {
+        return value, err
+    }
+    return value, err
+}
+
+func (this *DB) Has(key []byte) (bool, error) {
+    var err  error
+    var has bool
+    if this.db == nil {
+        return has, errors.New("db not yet open")
+    }
+    has, err = this.db.Has(key, nil)
+    if err != nil {
+        return has, err
+    }
+    return has, err
+}
+
+type Resolver = func(key []byte, val []byte) (ok bool)
+
+func (this *DB) First(sval []byte) ([]byte, bool, error) {
+    compf := func(key []byte, val []byte) (ok bool) {
+        if bytes.Equal(val, sval) {
+            return true
+        }
+        return false
+    }
+    return this.comp(compf)
+}
+
+func (this *DB) comp(resolver Resolver) ([]byte, bool, error) {
+    var err  error
+    var key  []byte
+    var ok bool
+
+    iter := this.db.NewIterator(nil, nil)
+    defer iter.Release()
+    for iter.Next() {
+        if resolver(iter.Key(), iter.Value()) {
+            ok = true
+            key = iter.Key()
+            break
+        }
+    }
+    err = iter.Error()
+    if err != nil {
+        return key, ok, err
+    }
+    return key, ok, err
+}
+
+
+func (this *DB) All(resolver Resolver) ([][]byte, bool, error) {
+    collect := make([][]byte, 0)
+    var ok bool
+    var err error
+
+    iter := this.db.NewIterator(nil, nil)
+    defer iter.Release()
+    for iter.Next() {
+        if resolver(iter.Key(), iter.Value()) {
+            ok = true
+            collect = append(collect, iter.Key())
+        }
+    }
+    err = iter.Error()
+    if err != nil {
+        return collect, ok, err
+    }
+    return collect, ok, err
+}
+
+type Executor = func(key []byte, val []byte) (stop bool)
+
+func (this *DB) Iter(executor Executor) error {
+    var err error
+    iter := this.db.NewIterator(nil, nil)
+    defer iter.Release()
+    for iter.Next() {
+        if executor(iter.Key(), iter.Value()) {
+            break
+        }
+    }
+    err = iter.Error()
+    if err != nil {
+        return err
+    }
+    return err
+}
+
+func (this *DB) Clean() error {
+    var err error
+    iter := this.db.NewIterator(nil, nil)
+    defer iter.Release()
+    for iter.Next() {
+        err = this.db.Delete(iter.Key(), nil)
+        if err != nil {
+            return err
+        }
+    }
+    err = iter.Error()
+    if err != nil {
+        return err
+    }
+    return err
+}
+
+
+func (this *DB) Close() {
+    if this.db != nil {
+        this.db.Close()
+    }
+}
+//EOF

pmkeyvdb/keyvdb_test.go

@@ -0,0 +1,63 @@
+//
+package pmkeyvdb
+
+import (
+    "testing"
+    "path/filepath"
+
+    "pmapp/tools"
+    "github.com/stretchr/testify/assert"
+)
+
+const dbname string = "tmp.leveldb"
+const repeat int    = 1024
+
+func TestHasher01SetGetRandKey(t *testing.T) {
+    var err error
+    dbpath := filepath.Join(t.TempDir(), dbname)
+    db := NewDB()
+    err = db.Open(dbpath)
+    defer db.Close()
+    if err != nil {
+        t.Fatal(err)
+    }
+    for i := 0; i < repeat; i++ {
+        key := tools.RandBytes(16)
+        ival := tools.RandBytes(128)
+        err = db.Set(key, ival)
+        if err != nil {
+            t.Fatal(err)
+        }
+        oval, err := db.Get(key)
+        if err != nil {
+            t.Fatal(err)
+        }
+        assert.Equal(t, ival, oval, nil)
+    }
+}
+
+func TestHasher02SetGetEqKey(t *testing.T) {
+    var err error
+    dbpath := filepath.Join(t.TempDir(), dbname)
+    db := NewDB()
+    err = db.Open(dbpath)
+    defer db.Close()
+    if err != nil {
+        t.Fatal(err)
+    }
+    key := tools.RandBytes(128)
+    for i := 0; i < repeat; i++ {
+        ival := tools.RandBytes(128)
+        err = db.Set(key, ival)
+        if err != nil {
+            t.Fatal(err)
+        }
+        oval, err := db.Get(key)
+        if err != nil {
+            t.Fatal(err)
+        }
+        assert.Equal(t, ival, oval, nil)
+    }
+}
+//EOF
+