From efd809ebc45ef23c06a02f53217241567f02d544 Mon Sep 17 00:00:00 2001
From: Igor Sfiligoi <isfiligoi@ucsd.edu>
Date: Fri, 1 Nov 2013 19:43:56 +0000
Subject: Add support for other endian

---
 src/lib/binaryXHR.js | 43 ++++++++++++++++++++++++++-----------------
 src/lib/rrdFile.js   |  8 ++++++++
 2 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/src/lib/binaryXHR.js b/src/lib/binaryXHR.js
index d91ad72..b92d732 100644
--- a/src/lib/binaryXHR.js
+++ b/src/lib/binaryXHR.js
@@ -37,6 +37,8 @@ function BinaryFile(strData, iDataOffset, iDataLength) {
 	var doubleMantExpLo=Math.pow(2,-52);
 	var doubleMantExpFast=Math.pow(2,-20);
 
+	var switch_endian = false;
+
 	this.getRawData = function() {
 		return data;
 	}
@@ -57,6 +59,13 @@ function BinaryFile(strData, iDataOffset, iDataLength) {
 	  throw new InvalidBinaryFile("Unsupported type " + (typeof strData));
 	}
 
+	this.getEndianByteAt = function(iOffset,width,delta) {
+	  if (this.switch_endian) 
+	    return this.getByteAt(iOffset+width-delta-1);
+	  else
+	    return this.getByteAt(iOffset+delta);
+	}
+
 	this.getLength = function() {
 		return dataLength;
 	}
@@ -70,7 +79,7 @@ function BinaryFile(strData, iDataOffset, iDataLength) {
 	}
 
 	this.getShortAt = function(iOffset) {
-		var iShort = (this.getByteAt(iOffset + 1) << 8) + this.getByteAt(iOffset)
+	        var iShort = (this.getEndianByteAt(iOffset,2,1) << 8) + this.getEndianByteAt(iOffset,2,0)
 		if (iShort < 0) iShort += 65536;
 		return iShort;
 	}
@@ -82,10 +91,10 @@ function BinaryFile(strData, iDataOffset, iDataLength) {
 			return iUShort;
 	}
 	this.getLongAt = function(iOffset) {
-		var iByte1 = this.getByteAt(iOffset),
-			iByte2 = this.getByteAt(iOffset + 1),
-			iByte3 = this.getByteAt(iOffset + 2),
-			iByte4 = this.getByteAt(iOffset + 3);
+	        var iByte1 = this.getEndianByteAt(iOffset,4,0),
+	             iByte2 = this.getEndianByteAt(iOffset,4,1),
+	             iByte3 = this.getEndianByteAt(iOffset,4,2),
+	             iByte4 = this.getEndianByteAt(iOffset,4,3);
 
 		var iLong = (((((iByte4 << 8) + iByte3) << 8) + iByte2) << 8) + iByte1;
 		if (iLong < 0) iLong += 4294967296;
@@ -117,14 +126,14 @@ function BinaryFile(strData, iDataOffset, iDataLength) {
 
 	// Added
 	this.getDoubleAt = function(iOffset) {
-		var iByte1 = this.getByteAt(iOffset),
-			iByte2 = this.getByteAt(iOffset + 1),
-			iByte3 = this.getByteAt(iOffset + 2),
-		        iByte4 = this.getByteAt(iOffset + 3),
-		        iByte5 = this.getByteAt(iOffset + 4),
-			iByte6 = this.getByteAt(iOffset + 5),
-			iByte7 = this.getByteAt(iOffset + 6),
-			iByte8 = this.getByteAt(iOffset + 7);
+	        var iByte1 = this.getEndianByteAt(iOffset,8,0),
+	             iByte2 = this.getEndianByteAt(iOffset,8,1),
+	             iByte3 = this.getEndianByteAt(iOffset,8,2),
+	             iByte4 = this.getEndianByteAt(iOffset,8,3),
+	             iByte5 = this.getEndianByteAt(iOffset,8,4),
+	             iByte6 = this.getEndianByteAt(iOffset,8,5),
+	             iByte7 = this.getEndianByteAt(iOffset,8,6),
+	             iByte8 = this.getEndianByteAt(iOffset,8,7);
 		var iSign=iByte8 >> 7;
 		var iExpRaw=((iByte8 & 0x7F)<< 4) + (iByte7 >> 4);
 		var iMantHi=((((((iByte7 & 0x0F) << 8) + iByte6) << 8) + iByte5) << 8) + iByte4;
@@ -141,10 +150,10 @@ function BinaryFile(strData, iDataOffset, iDataLength) {
 	// added
 	// Extracts only 4 bytes out of 8, loosing in precision (20 bit mantissa)
 	this.getFastDoubleAt = function(iOffset) {
-		var iByte5 = this.getByteAt(iOffset + 4),
-			iByte6 = this.getByteAt(iOffset + 5),
-			iByte7 = this.getByteAt(iOffset + 6),
-			iByte8 = this.getByteAt(iOffset + 7);
+	        var iByte5 = this.getEndianByteAt(iOffset,8,4),
+		     iByte6 = this.getEndianByteAt(iOffset,8,5),
+		     iByte7 = this.getEndianByteAt(iOffset,8,6),
+		     iByte8 = this.getEndianByteAt(iOffset,8,7);
 		var iSign=iByte8 >> 7;
 		var iExpRaw=((iByte8 & 0x7F)<< 4) + (iByte7 >> 4);
 		var iMant=((((iByte7 & 0x0F) << 8) + iByte6) << 8) + iByte5;
diff --git a/src/lib/rrdFile.js b/src/lib/rrdFile.js
index 81f7731..35a892b 100644
--- a/src/lib/rrdFile.js
+++ b/src/lib/rrdFile.js
@@ -217,6 +217,10 @@ RRDHeader.prototype.validate_rrd = function() {
   if (this.rrd_data.getLongAt(12)==0) {
     // not a double here... likely 64 bit
     this.float_align=8;
+    if (! (this.rrd_data.getDoubleAt(16)==8.642135e+130)) {
+      // uhm... wrong endian?
+      this.rrd_data.switch_endian=true;
+    }
     if (this.rrd_data.getDoubleAt(16)==8.642135e+130) {
       // now, is it all 64bit or only float 64 bit?
       if (this.rrd_data.getLongAt(28)==0) {
@@ -233,6 +237,10 @@ RRDHeader.prototype.validate_rrd = function() {
     }
   } else {
     /// should be 32 bit alignment
+    if (! (this.rrd_data.getDoubleAt(12)==8.642135e+130)) {
+      // uhm... wrong endian?
+      this.rrd_data.switch_endian=true;
+    }
     if (this.rrd_data.getDoubleAt(12)==8.642135e+130) {
       this.float_align=4;
       this.int_align=4;
-- 
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