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ggregory pushed a commit to branch master
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The following commit(s) were added to refs/heads/master by this push:
new 7d7b5ad6d Refactor magic numbers
7d7b5ad6d is described below
commit 7d7b5ad6d8ad5d09f5ab8b6eb34fd571565187d0
Author: Gary Gregory <garydgreg...@gmail.com>
AuthorDate: Wed Jan 1 11:16:53 2025 -0500
Refactor magic numbers
- Rename private methods
- Javadoc internals
- End sentences in a period in exception messages
---
.../gzip/GzipCompressorInputStream.java | 18 +++++-----
.../gzip/GzipCompressorOutputStream.java | 33 ++++++++++++------
.../compress/compressors/gzip/GzipUtils.java | 40 ++++++++++++++++++++--
3 files changed, 68 insertions(+), 23 deletions(-)
diff --git
a/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorInputStream.java
b/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorInputStream.java
index fab11a42f..1ba1828ee 100644
---
a/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorInputStream.java
+++
b/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorInputStream.java
@@ -267,7 +267,7 @@ public class GzipCompressorInputStream extends
CompressorInputStream implements
private boolean init(final boolean isFirstMember) throws IOException {
if (!isFirstMember && !decompressConcatenated) { // at least one must
be true
- throw new IllegalStateException("Unexpected: isFirstMember and
decompressConcatenated are both false!");
+ throw new IllegalStateException("Unexpected: isFirstMember and
decompressConcatenated are both false.");
}
parameters.setFileNameCharset(fileNameCharset);
// Check the magic bytes without a possibility of EOFException.
@@ -279,8 +279,8 @@ public class GzipCompressorInputStream extends
CompressorInputStream implements
return false;
}
- if (magic0 != 31 || in.read() != 139) {
- throw new IOException(isFirstMember ? "Input is not in the .gz
format" : "Unexpected data after a valid .gz stream");
+ if (magic0 != GzipUtils.ID1 || in.read() != GzipUtils.ID2) {
+ throw new IOException(isFirstMember ? "Input is not in the .gz
format." : "Unexpected data after a valid .gz stream.");
}
// Parsing the rest of the header may throw EOFException.
@@ -292,15 +292,15 @@ public class GzipCompressorInputStream extends
CompressorInputStream implements
final int flg = inData.readUnsignedByte();
if ((flg & GzipUtils.FRESERVED) != 0) {
- throw new IOException("Reserved flags are set in the .gz header");
+ throw new IOException("Reserved flags are set in the .gz header.");
}
parameters.setModificationTime(ByteUtils.fromLittleEndian(inData, 4));
switch (inData.readUnsignedByte()) { // extra flags
- case 2:
+ case GzipUtils.XFL_MAX_COMPRESSION:
parameters.setCompressionLevel(Deflater.BEST_COMPRESSION);
break;
- case 4:
+ case GzipUtils.XFL_MAX_SPEED:
parameters.setCompressionLevel(Deflater.BEST_SPEED);
break;
default:
@@ -384,7 +384,7 @@ public class GzipCompressorInputStream extends
CompressorInputStream implements
try {
ret = inflater.inflate(b, off, len);
} catch (final DataFormatException e) { // NOSONAR
- throw new IOException("Gzip-compressed data is corrupt", e);
+ throw new IOException("Gzip-compressed data is corrupt.", e);
}
crc.update(b, off, ret);
@@ -411,14 +411,14 @@ public class GzipCompressorInputStream extends
CompressorInputStream implements
final long crcStored = ByteUtils.fromLittleEndian(inData, 4);
if (crcStored != crc.getValue()) {
- throw new IOException("Gzip-compressed data is corrupt " +
"(CRC32 error)");
+ throw new IOException("Gzip-compressed data is corrupt
(CRC32 error).");
}
// Uncompressed size modulo 2^32 (ISIZE in the spec)
final long isize = ByteUtils.fromLittleEndian(inData, 4);
if (isize != (inflater.getBytesWritten() & 0xffffffffL)) {
- throw new IOException("Gzip-compressed data is corrupt" +
"(uncompressed size mismatch)");
+ throw new IOException("Gzip-compressed data is corrupt
(uncompressed size mismatch).");
}
// See if this is the end of the file.
diff --git
a/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorOutputStream.java
b/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorOutputStream.java
index 3496a9965..1f501e90e 100644
---
a/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorOutputStream.java
+++
b/src/main/java/org/apache/commons/compress/compressors/gzip/GzipCompressorOutputStream.java
@@ -25,7 +25,6 @@ import java.nio.ByteOrder;
import java.nio.charset.Charset;
import java.util.zip.CRC32;
import java.util.zip.Deflater;
-import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
import org.apache.commons.compress.compressors.CompressorOutputStream;
@@ -70,7 +69,7 @@ public class GzipCompressorOutputStream extends
CompressorOutputStream<OutputStr
this.deflater = new Deflater(parameters.getCompressionLevel(), true);
this.deflater.setStrategy(parameters.getDeflateStrategy());
this.deflateBuffer = new byte[parameters.getBufferSize()];
- writeHeader(parameters);
+ writeMemberHeader(parameters);
}
@Override
@@ -105,7 +104,7 @@ public class GzipCompressorOutputStream extends
CompressorOutputStream<OutputStr
while (!deflater.finished()) {
deflate();
}
- writeTrailer();
+ writeMemberTrailer();
}
}
@@ -127,7 +126,7 @@ public class GzipCompressorOutputStream extends
CompressorOutputStream<OutputStr
@Override
public void write(final byte[] buffer, final int offset, final int length)
throws IOException {
if (deflater.finished()) {
- throw new IOException("Cannot write more data, the end of the
compressed data stream has been reached");
+ throw new IOException("Cannot write more data, the end of the
compressed data stream has been reached.");
}
if (length > 0) {
deflater.setInput(buffer, offset, length);
@@ -144,7 +143,7 @@ public class GzipCompressorOutputStream extends
CompressorOutputStream<OutputStr
}
/**
- * Writes a NUL-terminated String encoded with the {@code charset}.
+ * Writes a C-style string, a NUL-terminated string, encoded with the
{@code charset}.
*
* @param value The String to write.
* @param charset Specifies the Charset to use.
@@ -160,13 +159,14 @@ public class GzipCompressorOutputStream extends
CompressorOutputStream<OutputStr
}
}
- private void writeHeader(final GzipParameters parameters) throws
IOException {
+ private void writeMemberHeader(final GzipParameters parameters) throws
IOException {
final String fileName = parameters.getFileName();
final String comment = parameters.getComment();
final byte[] extra = parameters.getExtraField() != null ?
parameters.getExtraField().toByteArray() : null;
final ByteBuffer buffer = ByteBuffer.allocate(10);
buffer.order(ByteOrder.LITTLE_ENDIAN);
- buffer.putShort((short) GZIPInputStream.GZIP_MAGIC);
+ buffer.put((byte) GzipUtils.ID1);
+ buffer.put((byte) GzipUtils.ID2);
buffer.put((byte) Deflater.DEFLATED); // compression method (8:
deflate)
buffer.put((byte) ((extra != null ? GzipUtils.FEXTRA : 0)
| (fileName != null ? GzipUtils.FNAME : 0)
@@ -177,11 +177,11 @@ public class GzipCompressorOutputStream extends
CompressorOutputStream<OutputStr
// extra flags
final int compressionLevel = parameters.getCompressionLevel();
if (compressionLevel == Deflater.BEST_COMPRESSION) {
- buffer.put((byte) 2);
+ buffer.put(GzipUtils.XFL_MAX_COMPRESSION);
} else if (compressionLevel == Deflater.BEST_SPEED) {
- buffer.put((byte) 4);
+ buffer.put(GzipUtils.XFL_MAX_SPEED);
} else {
- buffer.put((byte) 0);
+ buffer.put(GzipUtils.XFL_UNKNOWN);
}
buffer.put((byte) parameters.getOperatingSystem());
out.write(buffer.array());
@@ -204,7 +204,18 @@ public class GzipCompressorOutputStream extends
CompressorOutputStream<OutputStr
crc.reset();
}
- private void writeTrailer() throws IOException {
+ /**
+ * Writes the member trailer.
+ * <pre>
+ * 0 1 2 3 4 5 6 7
+ * +---+---+---+---+---+---+---+---+
+ * | CRC32 | ISIZE |
+ * +---+---+---+---+---+---+---+---+
+ * </pre>
+ *
+ * @throws IOException if an I/O error occurs.
+ */
+ private void writeMemberTrailer() throws IOException {
final ByteBuffer buffer = ByteBuffer.allocate(8);
buffer.order(ByteOrder.LITTLE_ENDIAN);
buffer.putInt((int) crc.getValue());
diff --git
a/src/main/java/org/apache/commons/compress/compressors/gzip/GzipUtils.java
b/src/main/java/org/apache/commons/compress/compressors/gzip/GzipUtils.java
index 5d8b99902..da4d5ea52 100644
--- a/src/main/java/org/apache/commons/compress/compressors/gzip/GzipUtils.java
+++ b/src/main/java/org/apache/commons/compress/compressors/gzip/GzipUtils.java
@@ -42,18 +42,49 @@ public class GzipUtils {
/** Header flag indicating a header CRC follows the header. */
static final int FHCRC = 0x02;
+ private static final FileNameUtil fileNameUtil;
+
/** Header flag indicating a file name follows the header. */
static final int FNAME = 0x08;
static final int FRESERVED = 0xE0;
- private static final FileNameUtil fileNameUtil;
-
/**
* Charset for file name and comments per the <a
href="https://tools.ietf.org/html/rfc1952";>GZIP File Format Specification</a>.
*/
static final Charset GZIP_ENCODING = StandardCharsets.ISO_8859_1;
+ /**
+ * Member header ID1 (IDentification 1).
+ *
+ * See <a
href="https://datatracker.ietf.org/doc/html/rfc1952#page-5";>RFC1952</a> 2.3.1.
Member header and trailer.
+ */
+ static final int ID1 = 31;
+
+ /**
+ * Member header ID2 (IDentification 2).
+ *
+ * See <a
href="https://datatracker.ietf.org/doc/html/rfc1952#page-5";>RFC1952</a> 2.3.1.
Member header and trailer.
+ */
+ static final int ID2 = 139;
+
+ /**
+ * Member header XFL (eXtra FLags) when the "deflate" method (CM = 8) is
set, then XFL = 2 means the compressor used maximum compression (slowest
+ * algorithm).
+ *
+ * See <a
href="https://datatracker.ietf.org/doc/html/rfc1952#page-5";>RFC1952</a> 2.3.1.
Member header and trailer.
+ */
+ static final byte XFL_MAX_COMPRESSION = 2;
+
+ /**
+ * Member header XFL (eXtra FLags) when the "deflate" method (CM = 8) is
set, then XFL = 4 means the compressor used the fastest algorithm.
+ *
+ * See <a
href="https://datatracker.ietf.org/doc/html/rfc1952#page-5";>RFC1952</a> 2.3.1.
Member header and trailer.
+ */
+ static final byte XFL_MAX_SPEED = 4;
+
+ static final byte XFL_UNKNOWN = 0;
+
static {
// using LinkedHashMap so .tgz is preferred over .taz as
// compressed extension of .tar as FileNameUtil will use the
@@ -72,7 +103,6 @@ public class GzipUtils {
uncompressSuffix.put("_z", "");
fileNameUtil = new FileNameUtil(uncompressSuffix, ".gz");
}
-
/**
* Maps the given file name to the name that the file should have after
compression with gzip. Common file types with custom suffixes for compressed
* versions are automatically detected and correctly mapped. For example
the name "package.tar" is mapped to "package.tgz". If no custom mapping is
@@ -99,6 +129,7 @@ public class GzipUtils {
public static String getCompressedFileName(final String fileName) {
return fileNameUtil.getCompressedFileName(fileName);
}
+
/**
* Maps the given name of a gzip-compressed file to the name that the file
should have after uncompression. Commonly used file type specific suffixes like
* ".tgz" or ".svgz" are automatically detected and correctly mapped. For
example the name "package.tgz" is mapped to "package.tar". And any file names
with
@@ -113,6 +144,7 @@ public class GzipUtils {
public static String getUncompressedFilename(final String fileName) {
return fileNameUtil.getUncompressedFileName(fileName);
}
+
/**
* Maps the given name of a gzip-compressed file to the name that the file
should have after uncompression. Commonly used file type specific suffixes like
* ".tgz" or ".svgz" are automatically detected and correctly mapped. For
example the name "package.tgz" is mapped to "package.tar". And any file names
with
@@ -126,6 +158,7 @@ public class GzipUtils {
public static String getUncompressedFileName(final String fileName) {
return fileNameUtil.getUncompressedFileName(fileName);
}
+
/**
* Detects common gzip suffixes in the given file name.
*
@@ -137,6 +170,7 @@ public class GzipUtils {
public static boolean isCompressedFilename(final String fileName) {
return fileNameUtil.isCompressedFileName(fileName);
}
+
/**
* Detects common gzip suffixes in the given file name.
*
