move CharsetVerifier to utils package

This commit is contained in:
Vincent Breitmoser
2016-02-23 14:14:12 +01:00
parent a0c90f0ad5
commit b9abf43153
3 changed files with 3 additions and 2 deletions

View File

@@ -1,142 +0,0 @@
package org.sufficientlysecure.keychain.operations;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import android.content.ClipDescription;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
/** This class can be used to guess whether a stream of data is encoded in a given
* charset or not.
*
* An object of this class must be initialized with a byte[] buffer, which should
* be filled with data, then processed with {@link #readBytesFromBuffer}. This can
* be done any number of times. Once all data has been read, a final status can be
* read using the getter methods.
*/
public class CharsetVerifier {
private final ByteBuffer bufWrap;
private final CharBuffer dummyOutput;
private final CharsetDecoder charsetDecoder;
private boolean isFinished;
private boolean isFaulty;
private boolean isGuessed;
private boolean isPossibleTextMimeType;
private boolean isTextMimeType;
private String charset;
public CharsetVerifier(@NonNull byte[] buf, String mimeType, @Nullable String charset) {
isPossibleTextMimeType = ClipDescription.compareMimeTypes(mimeType, "application/octet-stream")
|| ClipDescription.compareMimeTypes(mimeType, "application/x-download")
|| ClipDescription.compareMimeTypes(mimeType, "text/*");
if (!isPossibleTextMimeType) {
charsetDecoder = null;
bufWrap = null;
dummyOutput = null;
return;
}
isTextMimeType = ClipDescription.compareMimeTypes(mimeType, "text/*");
bufWrap = ByteBuffer.wrap(buf);
dummyOutput = CharBuffer.allocate(buf.length);
// the charset defaults to us-ascii, but we want to default to utf-8
if (charset == null || "us-ascii".equals(charset)) {
charset = "utf-8";
isGuessed = true;
} else {
isGuessed = false;
}
this.charset = charset;
charsetDecoder = Charset.forName(charset).newDecoder();
charsetDecoder.onMalformedInput(CodingErrorAction.REPORT);
charsetDecoder.onUnmappableCharacter(CodingErrorAction.REPORT);
charsetDecoder.reset();
}
public void readBytesFromBuffer(int pos, int len) {
if (isFinished) {
throw new IllegalStateException("cannot write again after reading charset status!");
}
if (isFaulty || bufWrap == null) {
return;
}
bufWrap.rewind();
bufWrap.position(pos);
bufWrap.limit(len);
dummyOutput.rewind();
CoderResult result = charsetDecoder.decode(bufWrap, dummyOutput, false);
if (result.isError()) {
isFaulty = true;
}
}
private void finishIfNecessary() {
if (isFinished || isFaulty || bufWrap == null) {
return;
}
isFinished = true;
bufWrap.rewind();
bufWrap.limit(0);
dummyOutput.rewind();
CoderResult result = charsetDecoder.decode(bufWrap, dummyOutput, true);
if (result.isError()) {
isFaulty = true;
}
}
public boolean isCharsetFaulty() {
finishIfNecessary();
return isFaulty;
}
public boolean isCharsetGuessed() {
finishIfNecessary();
return isGuessed;
}
public String getCharset() {
finishIfNecessary();
if (!isPossibleTextMimeType || (isGuessed && isFaulty)) {
return null;
}
return charset;
}
public String getMaybeFaultyCharset() {
return charset;
}
/** Returns true if the data which was read is definitely binary.
*
* This can happen when either the supplied mimeType indicated a non-ambiguous
* binary data type, or if we guessed a charset but got errors while decoding.
*/
public boolean isDefinitelyBinary() {
finishIfNecessary();
return !isTextMimeType && (!isPossibleTextMimeType || (isGuessed && isFaulty));
}
/** Returns true iff the data which was read is probably (or
* definitely) text.
*
* The corner case where isDefinitelyBinary returns false but isProbablyText
* returns true is where the charset was provided by the data (so is not
* guessed) but is still faulty.
*/
public boolean isProbablyText() {
finishIfNecessary();
return isTextMimeType || isPossibleTextMimeType && (!isGuessed || !isFaulty);
}
}

View File

@@ -53,6 +53,7 @@ import org.sufficientlysecure.keychain.provider.ProviderHelper;
import org.sufficientlysecure.keychain.provider.TemporaryFileProvider;
import org.sufficientlysecure.keychain.service.InputDataParcel;
import org.sufficientlysecure.keychain.service.input.CryptoInputParcel;
import org.sufficientlysecure.keychain.util.CharsetVerifier;
/** This operation deals with input data, trying to determine its type as it goes.