diff options
Diffstat (limited to 'src/jogl/classes/jogamp/opengl/util/pngj/PngIDatChunkInputStream.java')
| -rw-r--r-- | src/jogl/classes/jogamp/opengl/util/pngj/PngIDatChunkInputStream.java | 63 |
1 files changed, 39 insertions, 24 deletions
diff --git a/src/jogl/classes/jogamp/opengl/util/pngj/PngIDatChunkInputStream.java b/src/jogl/classes/jogamp/opengl/util/pngj/PngIDatChunkInputStream.java index 66c4b49f0..6cc39b0e6 100644 --- a/src/jogl/classes/jogamp/opengl/util/pngj/PngIDatChunkInputStream.java +++ b/src/jogl/classes/jogamp/opengl/util/pngj/PngIDatChunkInputStream.java @@ -11,23 +11,24 @@ import jogamp.opengl.util.pngj.chunks.ChunkHelper; /**
- * Reads IDAT chunks
+ * Reads a sequence of contiguous IDAT chunks
*/
class PngIDatChunkInputStream extends InputStream {
private final InputStream inputStream;
private final CRC32 crcEngine;
+ private boolean checkCrc = true;
private int lenLastChunk;
private byte[] idLastChunk = new byte[4];
private int toReadThisChunk = 0;
private boolean ended = false;
- private long offset; // offset inside inputstream
+ private long offset; // offset inside whole inputstream (counting bytes before IDAT)
// just informational
static class IdatChunkInfo {
public final int len;
- public final int offset;
+ public final long offset;
- private IdatChunkInfo(int len, int offset) {
+ private IdatChunkInfo(int len, long offset) {
this.len = len;
this.offset = offset;
}
@@ -38,16 +39,17 @@ class PngIDatChunkInputStream extends InputStream { /**
* Constructor must be called just after reading length and id of first IDAT chunk
**/
- PngIDatChunkInputStream(InputStream iStream, int lenFirstChunk, int offset) {
- this.offset = (long) offset;
+ PngIDatChunkInputStream(InputStream iStream, int lenFirstChunk, long offset) {
+ this.offset = offset;
inputStream = iStream;
- crcEngine = new CRC32();
this.lenLastChunk = lenFirstChunk;
toReadThisChunk = lenFirstChunk;
// we know it's a IDAT
System.arraycopy(ChunkHelper.b_IDAT, 0, idLastChunk, 0, 4);
+ crcEngine = new CRC32();
crcEngine.update(idLastChunk, 0, 4);
foundChunksInfo.add(new IdatChunkInfo(lenLastChunk, offset - 8));
+
// PngHelper.logdebug("IDAT Initial fragment: len=" + lenLastChunk);
if (this.lenLastChunk == 0)
endChunkGoForNext(); // rare, but...
@@ -58,31 +60,33 @@ class PngIDatChunkInputStream extends InputStream { */
@Override
public void close() throws IOException {
- super.close(); // nothing
+ super.close(); // thsi does nothing
}
private void endChunkGoForNext() {
- // Called after readging the last byte of chunk
+ // Called after readging the last byte of one IDAT chunk
// Checks CRC, and read ID from next CHUNK
// Those values are left in idLastChunk / lenLastChunk
// Skips empty IDATS
do {
- int crc = PngHelper.readInt4(inputStream); //
+ int crc = PngHelperInternal.readInt4(inputStream); //
offset += 4;
- int crccalc = (int) crcEngine.getValue();
- if (lenLastChunk > 0 && crc != crccalc)
- throw new PngjBadCrcException("error reading idat; offset: " + offset);
- crcEngine.reset();
- lenLastChunk = PngHelper.readInt4(inputStream);
- if (lenLastChunk < 0)
- throw new PngjInputException("invalid len for chunk: " + lenLastChunk);
+ if (checkCrc) {
+ int crccalc = (int) crcEngine.getValue();
+ if (lenLastChunk > 0 && crc != crccalc)
+ throw new PngjBadCrcException("error reading idat; offset: " + offset);
+ crcEngine.reset();
+ }
+ lenLastChunk = PngHelperInternal.readInt4(inputStream);
toReadThisChunk = lenLastChunk;
- PngHelper.readBytes(inputStream, idLastChunk, 0, 4);
+ PngHelperInternal.readBytes(inputStream, idLastChunk, 0, 4);
offset += 8;
+ // found a NON IDAT chunk? this stream is ended
ended = !Arrays.equals(idLastChunk, ChunkHelper.b_IDAT);
if (!ended) {
- foundChunksInfo.add(new IdatChunkInfo(lenLastChunk, (int) (offset - 8)));
- crcEngine.update(idLastChunk, 0, 4);
+ foundChunksInfo.add(new IdatChunkInfo(lenLastChunk, offset - 8));
+ if (checkCrc)
+ crcEngine.update(idLastChunk, 0, 4);
}
// PngHelper.logdebug("IDAT ended. next len= " + lenLastChunk + " idat?" +
// (!ended));
@@ -96,8 +100,9 @@ class PngIDatChunkInputStream extends InputStream { void forceChunkEnd() {
if (!ended) {
byte[] dummy = new byte[toReadThisChunk];
- PngHelper.readBytes(inputStream, dummy, 0, toReadThisChunk);
- crcEngine.update(dummy, 0, toReadThisChunk);
+ PngHelperInternal.readBytes(inputStream, dummy, 0, toReadThisChunk);
+ if (checkCrc)
+ crcEngine.update(dummy, 0, toReadThisChunk);
endChunkGoForNext();
}
}
@@ -107,11 +112,14 @@ class PngIDatChunkInputStream extends InputStream { */
@Override
public int read(byte[] b, int off, int len) throws IOException {
+ if (ended)
+ return -1; // can happen only when raw reading, see Pngreader.readAndSkipsAllRows()
if (toReadThisChunk == 0)
- throw new RuntimeException("this should not happen");
+ throw new PngjExceptionInternal("this should not happen");
int n = inputStream.read(b, off, len >= toReadThisChunk ? toReadThisChunk : len);
if (n > 0) {
- crcEngine.update(b, off, n);
+ if (checkCrc)
+ crcEngine.update(b, off, n);
this.offset += n;
toReadThisChunk -= n;
}
@@ -150,4 +158,11 @@ class PngIDatChunkInputStream extends InputStream { boolean isEnded() {
return ended;
}
+
+ /**
+ * Disables CRC checking. This can make reading faster
+ */
+ void disableCrcCheck() {
+ checkCrc = false;
+ }
}
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