import

pmscanner/scanner.go

@@ -0,0 +1,130 @@
+package pmscanner
+
+import (
+    "errors"
+    "fmt"
+    "os"
+    "io"
+    "strconv"
+    "encoding/hex"
+
+    "pmapp/pmhasher"
+    "pmapp/pmkeyvdb"
+)
+
+
+type Scanner struct {
+    bSize   int
+    keyvdb  *pmkeyvdb.DB
+    hasher  *pmhasher.Hasher
+}
+
+func NewScanner(dbname string, key []byte, bSize int) (*Scanner, error) {
+    var err error
+    scanner := &Scanner{}
+
+    keyvdb := pmkeyvdb.NewDB()
+    err = keyvdb.Open(dbname)
+    if err != nil {
+        return scanner, err
+    }
+    scanner.keyvdb = keyvdb
+
+    hasher, err := pmhasher.NewHahser(key)
+    if err != nil {
+        return scanner, err
+    }
+    scanner.hasher = hasher
+    scanner.bSize = bSize
+    return scanner, err
+}
+
+func (this *Scanner) Close() {
+    this.keyvdb.Close()
+}
+
+func (this *Scanner) Scan(filename string) error {
+    var err error
+
+    if this.keyvdb == nil {
+        return errors.New("db yet not open")
+    }
+
+    err = this.keyvdb.Clean()
+	if err != nil {
+		return err
+	}
+
+	file, err := os.OpenFile(filename, os.O_RDONLY, 0)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+    for {
+        buffer := make([]byte, this.bSize)
+        read, err := file.Read(buffer);
+        if  err == io.EOF {
+            break
+        }
+        hash, err := this.hasher.Hash(buffer[:read])
+        if err != nil {
+            return err
+        }
+        err = this.Inc(hash)
+        if err != nil {
+            return err
+        }
+    }
+    return err
+}
+
+func (this *Scanner) Print() error {
+    var err error
+    executor := func(key []byte, val []byte) bool {
+        keyHex := hex.EncodeToString(key)
+        counter, _ := strconv.Atoi(string(val))
+        if counter > 1 {
+            fmt.Println(keyHex, counter)
+        }
+        return false
+    }
+    err = this.keyvdb.Iter(executor)
+    if err != nil {
+        return err
+    }
+    return err
+}
+
+func (this *Scanner) Inc(key []byte) error {
+    var err error
+    var val []byte
+    has, err := this.keyvdb.Has(key)
+    if err != nil {
+        return err
+    }
+    if has {
+        val, err = this.keyvdb.Get(key)
+        if err != nil {
+            return err
+        }
+    }
+    var counter int
+    switch {
+        case len(val) == 0:
+            counter = 1
+        default:
+            counter, err = strconv.Atoi(string(val))
+            if err != nil {
+                return err
+            }
+            counter++
+    }
+    nval := []byte(strconv.Itoa(counter))
+    err = this.keyvdb.Set(key, nval)
+    if err != nil {
+        return err
+    }
+    return err
+}
+//EOF