diff options
Diffstat (limited to 'OpenPGP-Keychain/src/com/google/zxing/ReaderException.java')
-rw-r--r-- | OpenPGP-Keychain/src/com/google/zxing/ReaderException.java | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/OpenPGP-Keychain/src/com/google/zxing/ReaderException.java b/OpenPGP-Keychain/src/com/google/zxing/ReaderException.java new file mode 100644 index 000000000..224a497e5 --- /dev/null +++ b/OpenPGP-Keychain/src/com/google/zxing/ReaderException.java @@ -0,0 +1,98 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing; + +/** + * The general exception class throw when something goes wrong during decoding of a barcode. + * This includes, but is not limited to, failing checksums / error correction algorithms, being + * unable to locate finder timing patterns, and so on. + * + * @author Sean Owen + */ +public abstract class ReaderException extends Exception { + + // TODO: Currently we throw up to 400 ReaderExceptions while scanning a single 240x240 image before + // rejecting it. This involves a lot of overhead and memory allocation, and affects both performance + // and latency on continuous scan clients. In the future, we should change all the decoders not to + // throw exceptions for routine events, like not finding a barcode on a given row. Instead, we + // should return error codes back to the callers, and simply delete this class. In the mean time, I + // have altered this class to be as lightweight as possible, by ignoring the exception string, and + // by disabling the generation of stack traces, which is especially time consuming. These are just + // temporary measures, pending the big cleanup. + + //private static final ReaderException instance = new ReaderException(); + + // EXCEPTION TRACKING SUPPORT + // Identifies who is throwing exceptions and how often. To use: + // + // 1. Uncomment these lines and the code below which uses them. + // 2. Uncomment the two corresponding lines in j2se/CommandLineRunner.decode() + // 3. Change core to build as Java 1.5 temporarily +// private static int exceptionCount = 0; +// private static Map<String,Integer> throwers = new HashMap<String,Integer>(32); + + ReaderException() { + // do nothing + } + + //public static ReaderException getInstance() { +// Exception e = new Exception(); +// // Take the stack frame before this one. +// StackTraceElement stack = e.getStackTrace()[1]; +// String key = stack.getClassName() + "." + stack.getMethodName() + "(), line " + +// stack.getLineNumber(); +// if (throwers.containsKey(key)) { +// Integer value = throwers.get(key); +// value++; +// throwers.put(key, value); +// } else { +// throwers.put(key, 1); +// } +// exceptionCount++; + + //return instance; + //} + +// public static int getExceptionCountAndReset() { +// int temp = exceptionCount; +// exceptionCount = 0; +// return temp; +// } +// +// public static String getThrowersAndReset() { +// StringBuilder builder = new StringBuilder(1024); +// Object[] keys = throwers.keySet().toArray(); +// for (int x = 0; x < keys.length; x++) { +// String key = (String) keys[x]; +// Integer value = throwers.get(key); +// builder.append(key); +// builder.append(": "); +// builder.append(value); +// builder.append("\n"); +// } +// throwers.clear(); +// return builder.toString(); +// } + + // Prevent stack traces from being taken + // srowen says: huh, my IDE is saying this is not an override. native methods can't be overridden? + // This, at least, does not hurt. Because we use a singleton pattern here, it doesn't matter anyhow. + public final Throwable fillInStackTrace() { + return null; + } + +} |