diff options
| -rw-r--r-- | poi/src/main/java/org/apache/poi/util/IOUtils.java | 45 | ||||
| -rw-r--r-- | poi/src/test/java/org/apache/poi/util/TestIOUtils.java | 9 |
2 files changed, 39 insertions, 15 deletions
diff --git a/poi/src/main/java/org/apache/poi/util/IOUtils.java b/poi/src/main/java/org/apache/poi/util/IOUtils.java index 422b337e84..34fac68a58 100644 --- a/poi/src/main/java/org/apache/poi/util/IOUtils.java +++ b/poi/src/main/java/org/apache/poi/util/IOUtils.java @@ -60,13 +60,19 @@ public final class IOUtils { */ private static int MAX_BYTE_ARRAY_INIT_SIZE = -1; + /** + * The default size of the bytearray used while reading input streams. This is meant to be pretty small. + */ + private static int DEFAULT_BUFFER_SIZE = 4096; + private IOUtils() { // no instances of this class } /** * @param maxOverride the max init size of ByteArrayOutputStream. - * -1 (the default) means init size of ByteArrayOutputStream could be up to Integer.MAX_VALUE + * -1 (the default) means init size of ByteArrayOutputStream could be up to {@link Integer#MAX_VALUE} + * @since POI 5.2.2 */ public static void setMaxByteArrayInitSize(final int maxOverride) { MAX_BYTE_ARRAY_INIT_SIZE = maxOverride; @@ -74,7 +80,8 @@ public final class IOUtils { /** * @return the max init size of ByteArrayOutputStream. - * -1 (the default) means init size of ByteArrayOutputStream could be up to Integer.MAX_VALUE + * -1 (the default) means init size of ByteArrayOutputStream could be up to {@link Integer#MAX_VALUE} + * @since POI 5.2.2 */ public static int getMaxByteArrayInitSize() { return MAX_BYTE_ARRAY_INIT_SIZE; @@ -167,7 +174,7 @@ public final class IOUtils { * Reads up to {@code length} bytes from the input stream, and returns the bytes read. * * @param stream The byte stream of data to read. - * @param length The maximum length to read, use Integer.MAX_VALUE to read the stream + * @param length The maximum length to read, use {@link Integer#MAX_VALUE} to read the stream * until EOF. * @return A byte array with the read bytes. * @throws IOException If reading data fails or EOF is encountered too early for the given length. @@ -224,15 +231,13 @@ public final class IOUtils { } final int derivedLen = Math.min(length, derivedMaxLength); - int bufferLen = isLengthKnown ? derivedLen : Math.min(4096, derivedLen); - if (MAX_BYTE_ARRAY_INIT_SIZE > 0 && bufferLen > MAX_BYTE_ARRAY_INIT_SIZE) { - bufferLen = Math.min(bufferLen, MAX_BYTE_ARRAY_INIT_SIZE); - } - try (UnsynchronizedByteArrayOutputStream baos = new UnsynchronizedByteArrayOutputStream(bufferLen)) { - byte[] buffer = new byte[4096]; + final int byteArrayInitLen = calculateByteArrayInitLength(isLengthKnown, length, derivedMaxLength); + final int internalBufferLen = DEFAULT_BUFFER_SIZE; + try (UnsynchronizedByteArrayOutputStream baos = new UnsynchronizedByteArrayOutputStream(byteArrayInitLen)) { + byte[] buffer = new byte[internalBufferLen]; int totalBytes = 0, readBytes; do { - readBytes = stream.read(buffer, 0, Math.min(buffer.length, derivedLen - totalBytes)); + readBytes = stream.read(buffer, 0, Math.min(internalBufferLen, derivedLen - totalBytes)); totalBytes += Math.max(readBytes, 0); if (readBytes > 0) { baos.write(buffer, 0, readBytes); @@ -255,6 +260,16 @@ public final class IOUtils { } } + //open for testing + static int calculateByteArrayInitLength(final boolean isLengthKnown, final int length, final int maxLength) { + final int derivedLen = Math.min(length, maxLength); + final int bufferLen = isLengthKnown ? derivedLen : Math.min(DEFAULT_BUFFER_SIZE, derivedLen); + if (MAX_BYTE_ARRAY_INIT_SIZE > 0 && bufferLen > MAX_BYTE_ARRAY_INIT_SIZE) { + return Math.min(bufferLen, MAX_BYTE_ARRAY_INIT_SIZE); + } + return bufferLen; + } + private static void checkLength(long length, int maxLength) { if (BYTE_ARRAY_MAX_OVERRIDE > 0) { if (length > BYTE_ARRAY_MAX_OVERRIDE) { @@ -387,7 +402,7 @@ public final class IOUtils { * @throws IOException If copying the data fails. */ public static long copy(InputStream inp, OutputStream out, long limit) throws IOException { - final byte[] buff = new byte[4096]; + final byte[] buff = new byte[DEFAULT_BUFFER_SIZE]; long totalCount = 0; int readBytes = -1; do { @@ -428,7 +443,7 @@ public final class IOUtils { * Calculate checksum on input data */ public static long calculateChecksum(byte[] data) { - Checksum sum = new CRC32(); + final Checksum sum = new CRC32(); sum.update(data, 0, data.length); return sum.getValue(); } @@ -440,9 +455,9 @@ public final class IOUtils { * {@code IOUtils.calculateChecksum(IOUtils.toByteArray(stream))} */ public static long calculateChecksum(InputStream stream) throws IOException { - Checksum sum = new CRC32(); + final Checksum sum = new CRC32(); - byte[] buf = new byte[4096]; + final byte[] buf = new byte[DEFAULT_BUFFER_SIZE]; int count; while ((count = stream.read(buf)) != -1) { if (count > 0) { @@ -461,7 +476,7 @@ public final class IOUtils { */ public static void closeQuietly( final Closeable closeable ) { // no need to log a NullPointerException here - if(closeable == null) { + if (closeable == null) { return; } diff --git a/poi/src/test/java/org/apache/poi/util/TestIOUtils.java b/poi/src/test/java/org/apache/poi/util/TestIOUtils.java index b585a24fd3..1f55e980f6 100644 --- a/poi/src/test/java/org/apache/poi/util/TestIOUtils.java +++ b/poi/src/test/java/org/apache/poi/util/TestIOUtils.java @@ -168,6 +168,15 @@ final class TestIOUtils { } @Test + void testCalculateByteArrayInitLength() throws IOException { + assertEquals(4096, IOUtils.calculateByteArrayInitLength(false, 6000, 10000)); + assertEquals(3000, IOUtils.calculateByteArrayInitLength(false, 3000, 10000)); + assertEquals(3000, IOUtils.calculateByteArrayInitLength(false, 10000, 3000)); + assertEquals(10000, IOUtils.calculateByteArrayInitLength(true, 10000, 12000)); + assertEquals(10000, IOUtils.calculateByteArrayInitLength(true, 12000, 10000)); + } + + @Test void testSkipFully() throws IOException { try (InputStream is = new FileInputStream(TMP)) { long skipped = IOUtils.skipFully(is, 20000L); |