implement Timestamp96

lib/codecs/DateCodec.js

@@ -9,7 +9,41 @@ function encode (dt) {
   var seconds = Math.floor(millis / 1000)
   var nanos = (millis - seconds * 1000) * 1e6
 
-  if (nanos || seconds > 0xffffffff) {
+  if (seconds >> 34 !== 0) {
+    // Timestamp96
+    const encoded = Buffer.allocUnsafe(13)
+    encoded[0] = -1
+
+    encoded.writeUInt32BE(nanos, 1)
+
+    var hex = ''
+    if (seconds >= 0) {
+      const padhex = '0000000000000000'
+      hex = seconds.toString(16)
+      // add some padding
+      hex = padhex.slice(0, hex.length * -1) + hex
+    } else {
+      // encode seconds in 2's Complement 64Bit
+      // reverse sign
+      // keep all bits 0 and first 1 from right
+      // reverse all other bits
+      var bin = (seconds * -1).toString(2)
+      var i = bin.length - 1
+      while (bin[i] === '0') {
+        i--
+      }
+      bin = bin.slice(0, i).split('').map(function (bit) { return bit === '1' ? 0 : 1 }).join('') + bin.slice(i, bin.length)
+      // add some padding
+      const pad64 = '1111111111111111111111111111111111111111111111111111111111111111'
+      bin = pad64.slice(0, bin.length * -1) + bin
+      // convert to hex
+      bin.match(/.{1,8}/g).forEach(function (byte) {
+        hex += parseInt(byte, 2).toString(16)
+      })
+    }
+    encoded.write(hex, 5, 'hex')
+    return encoded
+  } else if (nanos || seconds > 0xffffffff) {
     // Timestamp64
     const encoded = Buffer.allocUnsafe(9)
     encoded[0] = -1
@@ -55,7 +89,31 @@ function decode (buf) {
       break
 
     case 12:
-      throw new Error('timestamp 96 is not yet implemented')
+      // timestamp 96 stores the number of seconds and nanoseconds that have elapsed
+      // since 1970-01-01 00:00:00 UTC in 64-bit signed integer and 32-bit unsigned integer
+
+      // get seconds in hex
+      var hex = buf.toString('hex', 4, 12)
+      // check if seconds is a negative number
+      if (parseInt(buf.toString('hex', 4, 6), 16) & 0x80) {
+        // convert to binary
+        var bin = ''
+        const pad8 = '00000000'
+        hex.match(/.{1,2}/g).forEach(function (byte) {
+          byte = parseInt(byte, 16).toString(2)
+          byte = pad8.slice(0, byte.length * -1) + byte
+          bin += byte
+        })
+        // decode seconds from 2's Complement 64Bit
+        // reverse all bits
+        // reverse sign
+        // remove one
+        seconds = -1 * parseInt(bin.split('').map(function (bit) { return bit === '1' ? 0 : 1 }).join(''), 2) - 1
+      } else {
+        seconds = parseInt(hex, 16)
+      }
+
+      nanoseconds = buf.readUInt32BE(0)
   }
 
   var millis = (seconds * 1000) + Math.round(nanoseconds / 1E6)