storage: save current import file/offset and resume from there (lian#138)

Author: mhanne

lib/bitcoin/storage/storage.rb

@@ -406,10 +406,16 @@ def rescan
       end
 
       # import satoshi bitcoind blk0001.dat blockchain file
-      def import filename, max_depth = nil
+      def import filename, opts = {}
+        opts[:resume_file] ||= File.join(ENV["HOME"], ".bitcoin-ruby", Bitcoin.network_name.to_s, "import_resume.state")
+        @resume = File.read(opts[:resume_file]).split("|").map(&:to_i)  if File.exist?(opts[:resume_file])
+
         if File.file?(filename)
           log.info { "Importing #{filename}" }
           File.open(filename) do |file|
+            @offset = @resume && @resume[1] ? @resume[1] : 0
+            file.seek(@offset)
+
             until file.eof?
               magic = file.read(4)
 
@@ -421,13 +427,18 @@ def import filename, max_depth = nil
               size = file.read(4).unpack("L")[0]
               blk = Bitcoin::P::Block.new(file.read(size))
               depth, chain = new_block(blk)
-              break  if max_depth && depth >= max_depth
+              break  if opts[:max_depth] && depth >= opts[:max_depth]
+
+              File.write(opts[:resume_file], [@import_file_num, @offset += (size + 8)].join("|"))
             end
           end
         elsif File.directory?(filename)
           Dir.entries(filename).sort.each do |file|
-            next  unless file =~ /^blk.*?\.dat$/
+            next  unless file =~ /^blk(\d+)\.dat$/
+            @import_file_num = $1.to_i
+            next  if @resume && @resume[0] && @resume[0] > @import_file_num
             import(File.join(filename, file), max_depth)
+            File.write(opts[:resume_file], [@import_file_num, 0].join("|"))
           end
         else
           raise "Import dir/file #{filename} not found"

spec/bitcoin/storage/reorg_spec.rb

@@ -264,17 +264,17 @@ def @store.in_sync?; true; end
     Bitcoin.network = :bitcoin
     # Disable difficulty check
     Bitcoin.network[:no_difficulty] = true
-    @store.import "./spec/bitcoin/fixtures/reorg/blk_0_to_4.dat"
+    @store.import "./spec/bitcoin/fixtures/reorg/blk_0_to_4.dat", resume_file: "/dev/null"
     @store.get_depth.should == 4
     @store.get_head.hash.should =~ /000000002f264d65040/
     balance("1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa").should == 10000000000
     balance("1NiEGXeURREqqMjCvjCeZn6SwEBZ9AdVet").should == 0
     balance("1KXFNhNtrRMfgbdiQeuJqnfD7dR4PhniyJ").should == 5000000000
     balance("1JyMKvPHkrCQd8jQrqTR1rBsAd1VpRhTiE").should == 10000000000
-    @store.import "./spec/bitcoin/fixtures/reorg/blk_3A.dat"
-    @store.import "./spec/bitcoin/fixtures/reorg/blk_4A.dat"
+    @store.import "./spec/bitcoin/fixtures/reorg/blk_3A.dat", resume_file: "/dev/null"
+    @store.import "./spec/bitcoin/fixtures/reorg/blk_4A.dat", resume_file: "/dev/null"
     @store.get_head.hash.should =~ /000000002f264d65040/
-    @store.import "./spec/bitcoin/fixtures/reorg/blk_5A.dat"
+    @store.import "./spec/bitcoin/fixtures/reorg/blk_5A.dat", resume_file: "/dev/null"
     @store.get_depth.should == 5
     @store.get_head.hash.should =~ /00000000195f85184e7/
     balance("1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa").should == 15000000000