Add Blobs.fromStream()

Author: mikera

convex-core/src/main/java/convex/core/data/Blobs.java

@@ -1,5 +1,8 @@
 package convex.core.data;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.util.Random;
 
 import org.bouncycastle.util.Arrays;
@@ -69,6 +72,23 @@ public static ABlob fromHex(AString a) {
 		return fromHex(a.toString());
 	}
 
+	/**
+	 * Reads an InputStream as a canonical Blob.
+	 *
+	 * @param inputStream Stream of data to read as UTF-8 string
+	 * @return Blob content of stream
+	 * @throws IOException 
+	 */
+	public static ABlob fromStream(InputStream inputStream) throws IOException {
+		ABlob result=Blob.EMPTY;
+		while (true) {
+			byte[] bs=inputStream.readNBytes(Blob.CHUNK_LENGTH);
+			if (bs.length==0) break;
+			result=result.append(Blob.wrap(bs));
+		}
+		return result;
+	}
+	
 	/**
 	 * Best effort attempt to parse a Blob. Must parse as a Blob of correct length
 	 * @param o Object expected to contain a Blob value

convex-core/src/main/java/convex/core/util/Utils.java

@@ -723,7 +723,13 @@ public static String readResourceAsString(String path) throws IOException {
 		}
 	}
 
-
+	/**
+	 * Gets a resource as a Stream.
+	 *
+	 * @param path Path to resource, e.g "/actors/token.cvx"
+	 * @return String content of resource file
+	 * @throws IOException If an IO error occurs
+	 */
 	public static InputStream getResourceAsStream(String path) throws IOException {
 		InputStream inputStream = Utils.class.getResourceAsStream(path);
 		if (inputStream == null) throw new IOException("Resource not found: " + path);

convex-core/src/test/java/convex/core/data/BlobsTest.java

@@ -9,6 +9,7 @@
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.Random;
@@ -656,6 +657,22 @@ public void testBlobParse() {
 		assertEquals(b,Blobs.parse(" 0x"+hex+" "));
 		assertEquals(b,Blobs.parse(" "+hex+" "));
 	}
+	
+	@Test
+	public void testBlobFromStream() throws IOException {
+		doBlobStreamTest(Blobs.empty());
+		doBlobStreamTest(Samples.SMALL_BLOB);
+		
+		doBlobStreamTest(Samples.FULL_BLOB);
+		doBlobStreamTest(Samples.FULL_BLOB_PLUS);
+	}
+
+	private void doBlobStreamTest(ABlob b) throws IOException {
+		byte[] bs=b.getBytes();
+		ByteArrayInputStream bis=new ByteArrayInputStream(bs);
+		ABlob r=Blobs.fromStream(bis);
+		assertEquals(b,r);
+	}
 
 	@Test
 	public void testBlobEncoding() throws BadFormatException {