--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nsis/download_mirror.nsh	Sat May 14 01:12:35 2011 -0700
@@ -0,0 +1,249 @@
+var RandomSeed		# The seed for the random number generator
+ 
+###############################################################
+#
+# Returns a random number
+#
+# Usage:
+# 	Push Seed (or previously generated number)
+#	Call RandomNumber
+#	Pop Generated Random Number
+Function RandomNumber
+	Exch $R0
+ 
+	IntOp $R0 $R0 * "13"
+	IntOp $R0 $R0 + "3"
+	IntOp $R0 $R0 % "1048576" # Values goes from 0 to 1048576 (2^20)
+ 
+	Exch $R0
+FunctionEnd
+ 
+####################################################
+#
+# Returns a random number between 0 and MaxValue-1
+#
+# Usage:
+# 	Push Seed (or previously generated number)
+#	Push MaxValue
+#	Call RandomNumber
+#	Pop Generated Random Number
+#	Pop NewSeed
+Function LimitedRandomNumber
+	Exch $R0
+	Exch
+	Exch $R1
+	Push $R2
+	Push $R3
+ 
+	StrLen $R2 $R0
+	Push $R1
+RandLoop:
+	Call RandomNumber
+	Pop $R1	#Random Number
+	IntCmp $R1 $R0 0 NewRnd
+	StrLen $R3 $R1	
+	IntOp $R3 $R3 - $R2
+	IntOp $R3 $R3 / "2"
+	StrCpy $R3 $R1 $R2 $R3
+	IntCmp $R3 $R0 0 RndEnd
+NewRnd:
+	Push $R1
+	Goto RandLoop
+RndEnd:
+	StrCpy $R0 $R3
+	IntOp $R0 $R0 + "0" #removes initial 0's
+	Pop $R3
+	Pop $R2
+	Exch $R1
+	Exch
+	Exch $R0
+FunctionEnd
+
+###################################################
+# 
+# Downloads a file from a list of mirrors
+# (the fist mirror is selected at random)
+#
+# Usage:
+# 	Push Mirror1
+# 	[Push Mirror2]
+# 	...
+# 	[Push Mirror10]
+#	Push NumMirrors		# 10 Max
+#	Push FileName
+#	Call DownloadFromRandomMirror
+#	Pop Return
+#
+#	Returns the last NSISdl result
+Function DownloadFromRandomMirror
+	Exch $R1 #File name
+	Exch
+	Exch $R0 #Number of Mirrors
+	Push $0
+	Exch 3
+	Pop $0	#Mirror 1
+	IntCmpU "2" $R0 0 0 +4
+		Push $1
+		Exch 4
+		Pop $1	#Mirror 2
+	IntCmpU "3" $R0 0 0 +4
+		Push $2
+		Exch 5
+		Pop $2	#Mirror 3
+	IntCmpU "4" $R0 0 0 +4
+		Push $3
+		Exch 6
+		Pop $3	#Mirror 4
+	IntCmpU "5" $R0 0 0 +4
+		Push $4
+ 
+		Exch 7
+		Pop $4	#Mirror 5
+	IntCmpU "6" $R0 0 0 +4
+		Push $5
+		Exch 8
+		Pop $5	#Mirror 6
+	IntCmpU "7" $R0 0 0 +4
+		Push $6
+		Exch 9
+		Pop $6	#Mirror 7
+	IntCmpU "8" $R0 0 0 +4
+		Push $7
+		Exch 10
+		Pop $7	#Mirror 8
+	IntCmpU "9" $R0 0 0 +4
+		Push $8
+		Exch 11
+		Pop $8	#Mirror 9
+	IntCmpU "10" $R0 0 0 +4
+		Push $9
+		Exch 12
+		Pop $9	#Mirror 10
+	Push $R4
+	Push $R2
+	Push $R3
+	Push $R5
+	Push $R6
+ 
+	StrCmp $RandomSeed "" 0 +2
+		StrCpy $RandomSeed $HWNDPARENT   #init RandomSeed
+ 
+	Push $RandomSeed
+	Push $R0
+	Call LimitedRandomNumber
+	Pop $R3
+	Pop $RandomSeed
+ 
+	StrCpy $R5 "0"
+MirrorsStart:
+	IntOp $R5 $R5 + "1"
+	StrCmp $R3 "0" 0 +3
+		StrCpy $R2 $0
+		Goto MirrorsEnd
+	StrCmp $R3 "1" 0 +3
+		StrCpy $R2 $1
+		Goto MirrorsEnd
+	StrCmp $R3 "2" 0 +3
+		StrCpy $R2 $2
+		Goto MirrorsEnd
+	StrCmp $R3 "3" 0 +3
+		StrCpy $R2 $3
+		Goto MirrorsEnd
+	StrCmp $R3 "4" 0 +3
+		StrCpy $R2 $4
+		Goto MirrorsEnd
+	StrCmp $R3 "5" 0 +3
+		StrCpy $R2 $5
+		Goto MirrorsEnd
+	StrCmp $R3 "6" 0 +3
+		StrCpy $R2 $6
+		Goto MirrorsEnd
+	StrCmp $R3 "7" 0 +3
+		StrCpy $R2 $7
+		Goto MirrorsEnd
+	StrCmp $R3 "8" 0 +3
+		StrCpy $R2 $8
+		Goto MirrorsEnd
+	StrCmp $R3 "9" 0 +3
+		StrCpy $R2 $9
+		Goto MirrorsEnd
+	StrCmp $R3 "10" 0 +3
+		StrCpy $R2 $10
+		Goto MirrorsEnd
+ 
+MirrorsEnd:
+	IntOp $R6 $R3 + "1"
+	DetailPrint "Downloading from mirror $R6: $R2"
+ 
+	NSISdl::download "$R2" "$R1"
+	Pop $R4
+	StrCmp $R4 "success" Success
+	StrCmp $R4 "cancel" DownloadCanceled
+	IntCmp $R5 $R0 NoSuccess
+	DetailPrint "Download failed (error $R4), trying with other mirror"
+	IntOp $R3 $R3 + "1"
+	IntCmp $R3 $R0 0 MirrorsStart
+	StrCpy $R3 "0"
+	Goto MirrorsStart
+ 
+DownloadCanceled:
+	DetailPrint "Download Canceled: $R2"
+	Goto End
+NoSuccess:		
+	DetailPrint "Download Failed: $R1"
+	Goto End
+Success:
+	DetailPrint "Download completed."
+End:
+	Pop $R6
+	Pop $R5
+	Pop $R3
+	Pop $R2
+	Push $R4
+	Exch
+	Pop $R4
+	Exch 2
+	Pop $R1
+	Exch 2
+	Pop $0
+	Exch
+ 
+	IntCmpU "2" $R0 0 0 +4
+		Exch 2	
+		Pop $1
+		Exch
+	IntCmpU "3" $R0 0 0 +4
+		Exch 2	
+		Pop $2
+		Exch
+	IntCmpU "4" $R0 0 0 +4
+		Exch 2	
+		Pop $3
+		Exch
+	IntCmpU "5" $R0 0 0 +4
+		Exch 2	
+		Pop $4
+		Exch
+	IntCmpU "6" $R0 0 0 +4
+		Exch 2	
+		Pop $5
+		Exch
+	IntCmpU "7" $R0 0 0 +4
+		Exch 2	
+		Pop $6
+		Exch
+	IntCmpU "8" $R0 0 0 +4
+		Exch 2	
+		Pop $7
+		Exch
+	IntCmpU "9" $R0 0 0 +4
+		Exch 2	
+		Pop $8
+		Exch
+	IntCmpU "10" $R0 0 0 +4
+		Exch 2	
+		Pop $9
+		Exch
+	Pop $R0
+FunctionEnd
+