Sharing org.simantics.acorn for everyone to use

[simantics/platform.git] / bundles / org.simantics.acorn / src / org / simantics / acorn / HeadState.java

diff --git a/bundles/org.simantics.acorn/src/org/simantics/acorn/HeadState.java b/bundles/org.simantics.acorn/src/org/simantics/acorn/HeadState.java
new file mode 100644 (file)
index 0000000..56ef481
--- /dev/null
+++ b/bundles/org.simantics.acorn/src/org/simantics/acorn/HeadState.java
@@ -0,0 +1,105 @@
+package org.simantics.acorn;
+
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import org.simantics.databoard.Bindings;
+import org.simantics.databoard.binding.mutable.MutableVariant;
+import org.simantics.databoard.serialization.Serializer;
+import org.simantics.databoard.util.binary.BinaryMemory;
+
+public class HeadState {
+
+    public int headChangeSetId = 0;
+    public long transactionId = 1;
+    public long reservedIds = 3;
+
+    public ArrayList<String> clusters = new ArrayList<>();
+    public ArrayList<String> files = new ArrayList<>();
+    public ArrayList<String> stream = new ArrayList<>();
+    public ArrayList<String> cs = new ArrayList<>();
+//    public ArrayList<String> ccs = new ArrayList<String>();
+
+    public static HeadState load(Path directory) throws InvalidHeadStateException {
+        Path f = directory.resolve("head.state");
+        
+        try {
+            byte[] bytes = Files.readAllBytes(f);
+            MessageDigest sha1 = MessageDigest.getInstance("SHA-1");
+            int digestLength = sha1.getDigestLength();
+            
+            sha1.update(bytes, digestLength, bytes.length - digestLength);
+            byte[] newChecksum = sha1.digest();
+            if (!Arrays.equals(newChecksum, Arrays.copyOfRange(bytes, 0, digestLength))) {
+                throw new InvalidHeadStateException(
+                        "Checksum " + Arrays.toString(newChecksum) + " does not match excpected "
+                                + Arrays.toString(Arrays.copyOfRange(bytes, 0, digestLength)) + " for " + f.toAbsolutePath());
+            }
+            
+            HeadState object = (HeadState) org.simantics.databoard.Files.readFile(new ByteArrayInputStream(bytes, digestLength, bytes.length - digestLength), Bindings.getBindingUnchecked(HeadState.class));
+            return object;
+            
+        } catch (IOException i) {
+            return new HeadState();
+//            throw new InvalidHeadStateException(i);
+        } catch (NoSuchAlgorithmException e) {
+            throw new Error("SHA-1 Algorithm not found", e);
+        } catch (Throwable t) {
+            throw new InvalidHeadStateException(t);
+        }
+    }
+    
+    public void save(Path directory) throws IOException {
+        Path f = directory.resolve("head.state");
+        try {
+            File file = f.toFile();
+            BinaryMemory rf = new BinaryMemory(4096);
+            try {
+                MutableVariant v = new MutableVariant(Bindings.getBindingUnchecked(HeadState.class), this);
+                Serializer s = Bindings.getSerializerUnchecked( Bindings.VARIANT );
+                s.serialize(v, file);
+            } finally {
+                rf.close();
+            }
+            
+            byte[] bytes = rf.toByteBuffer().array();
+            
+            MessageDigest sha1 = MessageDigest.getInstance("SHA-1");
+            sha1.update(bytes);
+            byte[] checksum = sha1.digest();
+            
+            try (OutputStream out = Files.newOutputStream(f)) {
+                out.write(checksum);
+                out.write(bytes);
+            }
+            FileIO.syncPath(f);
+        } catch (NoSuchAlgorithmException e) {
+            throw new Error("SHA-1 digest not found, should not happen", e);
+        }
+    }
+
+    public static void validateHeadStateIntegrity(Path headState) throws InvalidHeadStateException, IOException {
+        try {
+            byte[] bytes = Files.readAllBytes(headState);
+            MessageDigest sha1 = MessageDigest.getInstance("SHA-1");
+            int digestLength = sha1.getDigestLength();
+            sha1.update(bytes, digestLength, bytes.length - digestLength);
+            byte[] newChecksum = sha1.digest();
+            if (!Arrays.equals(newChecksum, Arrays.copyOfRange(bytes, 0, digestLength))) {
+                throw new InvalidHeadStateException(
+                        "Checksum " + Arrays.toString(newChecksum) + " does not match excpected "
+                                + Arrays.toString(Arrays.copyOfRange(bytes, 0, digestLength)) + " for " + headState.toAbsolutePath());
+            }
+        } catch (NoSuchAlgorithmException e) {
+            throw new Error("SHA-1 digest not found, should not happen", e);
+        }
+    }
+}