Removed as many exceptions as possible from the C++ product readers

to improve performance. There is no change in the number of images
which pass the unit tests.


git-svn-id: https://zxing.googlecode.com/svn/trunk@1535 59b500cc-1b3d-0410-9834-0bbf25fbcc57

cpp/core/src/zxing/oned/EAN13Reader.cpp

@@ -30,7 +30,7 @@ namespace zxing {
     EAN13Reader::EAN13Reader() { }
 
     int EAN13Reader::decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen,
-        std::string& resultString){
+        std::string& resultString) {
       const int countersLen = 4;
       int counters[countersLen] = { 0, 0, 0, 0 };
 
@@ -41,6 +41,9 @@ namespace zxing {
       for (int x = 0; x < 6 && rowOffset < end; x++) {
         int bestMatch = decodeDigit(row, counters, countersLen, rowOffset,
             UPC_EAN_PATTERNS_L_AND_G_PATTERNS);
+        if (bestMatch < 0) {
+          return -1;
+        }
         resultString.append(1, (char) ('0' + bestMatch % 10));
         for (int i = 0; i < countersLen; i++) {
           rowOffset += counters[i];
@@ -50,39 +53,41 @@ namespace zxing {
         }
       }
 
-      determineFirstDigit(resultString, lgPatternFound);
+      if (!determineFirstDigit(resultString, lgPatternFound)) {
+        return -1;
+      }
 
-      int* middleRange = 0;
+      int* middleRange = findGuardPattern(row, rowOffset, true, (int*)getMIDDLE_PATTERN(),
-      try {
-        middleRange = findGuardPattern(row, rowOffset, true, (int*)getMIDDLE_PATTERN(),
             getMIDDLE_PATTERN_LEN());
+      if (middleRange != NULL) {
         rowOffset = middleRange[1];
-
         for (int x = 0; x < 6 && rowOffset < end; x++) {
           int bestMatch = decodeDigit(row, counters, countersLen, rowOffset,
               UPC_EAN_PATTERNS_L_PATTERNS);
+          if (bestMatch < 0) {
+            delete [] middleRange;
+            return -1;
+          }
           resultString.append(1, (char) ('0' + bestMatch));
           for (int i = 0; i < countersLen; i++) {
-              rowOffset += counters[i];
+            rowOffset += counters[i];
           }
         }
 
         delete [] middleRange;
         return rowOffset;
-      } catch (ReaderException const& re) {
-          delete [] middleRange;
-          throw re;
       }
+      return -1;
     }
 
-    void EAN13Reader::determineFirstDigit(std::string& resultString, int lgPatternFound) {
+    bool EAN13Reader::determineFirstDigit(std::string& resultString, int lgPatternFound) {
       for (int d = 0; d < 10; d++) {
         if (lgPatternFound == FIRST_DIGIT_ENCODINGS[d]) {
           resultString.insert(0, 1, (char) ('0' + d));
-          return;
+          return true;
         }
       }
-      throw ReaderException("determineFirstDigit");
+      return false;
     }
 
     BarcodeFormat EAN13Reader::getBarcodeFormat(){

cpp/core/src/zxing/oned/EAN13Reader.h

@@ -26,15 +26,16 @@
 namespace zxing {
 	namespace oned {
 		class EAN13Reader : public UPCEANReader {
-			
+
 		private:
-			static void determineFirstDigit(std::string& resultString, int lgPatternFound);								//throws ReaderException
+			static bool determineFirstDigit(std::string& resultString, int lgPatternFound);
-			
+
 		public:
 			EAN13Reader();
-			
+
-			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen, std::string& resultString);			//throws ReaderException
+			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen,
-			
+			    std::string& resultString);
+
 			BarcodeFormat getBarcodeFormat();
 		};
 	}

cpp/core/src/zxing/oned/EAN8Reader.cpp

@@ -36,21 +36,26 @@ namespace zxing {
       for (int x = 0; x < 4 && rowOffset < end; x++) {
         int bestMatch = decodeDigit(row, counters, countersLen, rowOffset,
             UPC_EAN_PATTERNS_L_PATTERNS);
+        if (bestMatch < 0) {
+          return -1;
+        }
         resultString.append(1, (char) ('0' + bestMatch));
         for (int i = 0; i < countersLen; i++) {
           rowOffset += counters[i];
         }
       }
 
-      int* middleRange = 0;
+      int* middleRange = findGuardPattern(row, rowOffset, true, (int*)getMIDDLE_PATTERN(),
-      try {
-        middleRange = findGuardPattern(row, rowOffset, true, (int*)getMIDDLE_PATTERN(),
             getMIDDLE_PATTERN_LEN());
+      if (middleRange != NULL) {
         rowOffset = middleRange[1];
-
         for (int x = 0; x < 4 && rowOffset < end; x++) {
           int bestMatch = decodeDigit(row, counters, countersLen, rowOffset,
               UPC_EAN_PATTERNS_L_PATTERNS);
+          if (bestMatch < 0) {
+            delete [] middleRange;
+            return -1;
+          }
           resultString.append(1, (char) ('0' + bestMatch));
           for (int i = 0; i < countersLen; i++) {
             rowOffset += counters[i];
@@ -59,10 +64,8 @@ namespace zxing {
 
         delete [] middleRange;
         return rowOffset;
-      } catch (ReaderException const& re) {
-        delete [] middleRange;
-        throw re;
       }
+      return -1;
     }
 
     BarcodeFormat EAN8Reader::getBarcodeFormat(){

cpp/core/src/zxing/oned/EAN8Reader.h

@@ -26,12 +26,13 @@
 namespace zxing {
 	namespace oned {
 		class EAN8Reader : public UPCEANReader {
-			
+
 		public:
 			EAN8Reader();
-			
+
-			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen, std::string& resultString);			//throws ReaderException
+			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen,
-			
+			    std::string& resultString);
+
 			BarcodeFormat getBarcodeFormat();
 		};
 	}

cpp/core/src/zxing/oned/OneDReader.cpp

@@ -31,13 +31,12 @@ namespace zxing {
 		}
 
 		Ref<Result> OneDReader::decode(Ref<BinaryBitmap> image, DecodeHints hints) {
-		  try {
+		  Ref<Result> result = doDecode(image, hints);
-				return doDecode(image, hints);
+		  if (result.empty() && hints.getTryHarder() && image->isRotateSupported()) {
-			} catch (ReaderException re) {
+		    Ref<BinaryBitmap> rotatedImage(image->rotateCounterClockwise());
-				if (hints.getTryHarder() && image->isRotateSupported()) {
+				result = doDecode(rotatedImage, hints);
-					Ref<BinaryBitmap> rotatedImage(image->rotateCounterClockwise());
+				if (!result.empty()) {
-					Ref<Result> result(doDecode(rotatedImage, hints));
+				  /*
-					/*
 					// Record that we found it rotated 90 degrees CCW / 270 degrees CW
 					Hashtable metadata = result.getResultMetadata();
 					int orientation = 270;
@@ -54,11 +53,12 @@ namespace zxing {
 					for (size_t i = 0; i < points.size(); i++) {
 						points[i].reset(new OneDResultPoint(height - points[i]->getY() - 1, points[i]->getX()));
 					}
-					return result;
-				} else {
-					throw re;
 				}
-			}
+		  }
+		  if (result.empty()) {
+		    throw ReaderException("");
+		  }
+		  return result;
 		}
 
 		Ref<Result> OneDReader::doDecode(Ref<BinaryBitmap> image, DecodeHints hints) {
@@ -127,7 +127,7 @@ namespace zxing {
           }
 				}
 			}
-			throw ReaderException("doDecode() failed");
+			return Ref<Result>();
 		}
 
 		unsigned int OneDReader::patternMatchVariance(int counters[], int countersSize,

cpp/core/src/zxing/oned/UPCAReader.h

@@ -25,20 +25,21 @@
 namespace zxing {
 	namespace oned {
 		class UPCAReader : public UPCEANReader {
-			
+
 		private:
 			EAN13Reader ean13Reader;
-			static Ref<Result> maybeReturnResult(Ref<Result> result);														//throws ReaderException
+			static Ref<Result> maybeReturnResult(Ref<Result> result);
-			
+
 		public:
 			UPCAReader();
-			
+
-			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen, std::string& resultString);			//throws ReaderException
+			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen,
-			
+			    std::string& resultString);
-			Ref<Result> decodeRow(int rowNumber, Ref<BitArray> row);														//throws ReaderException
+
-			Ref<Result> decodeRow(int rowNumber, Ref<BitArray> row, int startGuardRange[]);									//throws ReaderException
+			Ref<Result> decodeRow(int rowNumber, Ref<BitArray> row);
+			Ref<Result> decodeRow(int rowNumber, Ref<BitArray> row, int startGuardRange[]);
 			Ref<Result> decode(Ref<BinaryBitmap> image, DecodeHints hints);
-			
+
 			BarcodeFormat getBarcodeFormat();
 		};
 	}

cpp/core/src/zxing/oned/UPCEANReader.cpp

@@ -95,86 +95,85 @@ namespace zxing {
 
 
     Ref<Result> UPCEANReader::decodeRow(int rowNumber, Ref<BitArray> row) {
-			int* start = NULL;
+			int* start = findStartGuardPattern(row);
-			try {
+			if (start != NULL) {
-				start = findStartGuardPattern(row);
+        try {
-				Ref<Result> result = decodeRow(rowNumber, row, start);
+          Ref<Result> result = decodeRow(rowNumber, row, start);
-				delete [] start;
+          delete [] start;
-				return result;
+          return result;
-			} catch (ReaderException const& re) {
+        } catch (ReaderException const& re) {
-				delete [] start;
+          delete [] start;
-				return Ref<Result>();
+        }
 			}
+			return Ref<Result>();
     }
 
     Ref<Result> UPCEANReader::decodeRow(int rowNumber, Ref<BitArray> row, int startGuardRange[]) {
-      int* endRange = NULL;
+      std::string tmpResultString;
-      try {
+      std::string& tmpResultStringRef = tmpResultString;
-				std::string tmpResultString;
+      int endStart = decodeMiddle(row, startGuardRange, 2 /*reference findGuardPattern*/ ,
-        std::string& tmpResultStringRef = tmpResultString;
+          tmpResultStringRef);
-        int endStart = decodeMiddle(row, startGuardRange, 2 /*reference findGuardPattern*/ ,
+      if (endStart < 0) {
-            tmpResultStringRef);
+        return Ref<Result>();
-        endRange = decodeEnd(row, endStart);
+      }
+      int* endRange = decodeEnd(row, endStart);
+      if (endRange == NULL) {
+        return Ref<Result>();
+      }
 
-        // Make sure there is a quiet zone at least as big as the end pattern after the barcode.
+      // Make sure there is a quiet zone at least as big as the end pattern after the barcode.
-        // The spec might want more whitespace, but in practice this is the maximum we can count on.
+      // The spec might want more whitespace, but in practice this is the maximum we can count on.
-        size_t end = endRange[1];
+      size_t end = endRange[1];
-        size_t quietEnd = end + (end - endRange[0]);
+      size_t quietEnd = end + (end - endRange[0]);
-        if (quietEnd >= row->getSize() || !row->isRange(end, quietEnd, false)) {
+      if (quietEnd >= row->getSize() || !row->isRange(end, quietEnd, false)) {
-          throw ReaderException("Quiet zone asserrt fail.");
-        }
-
-        if (!checkChecksum(tmpResultString)) {
-          throw ReaderException("Checksum fail.");
-        }
-
-        Ref<String> resultString(new String(tmpResultString));
-
-        float left = (float) (startGuardRange[1] + startGuardRange[0]) / 2.0f;
-        float right = (float) (endRange[1] + endRange[0]) / 2.0f;
-
-        std::vector< Ref<ResultPoint> > resultPoints(2);
-        Ref<OneDResultPoint> resultPoint1(new OneDResultPoint(left, (float) rowNumber));
-        Ref<OneDResultPoint> resultPoint2(new OneDResultPoint(right, (float) rowNumber));
-        resultPoints[0] = resultPoint1;
-        resultPoints[1] = resultPoint2;
-
-        ArrayRef<unsigned char> resultBytes(1);
-
-        Ref<Result> res(new Result(resultString, resultBytes, resultPoints, getBarcodeFormat()));
         delete [] endRange;
-        return res;
+        return Ref<Result>();
-      } catch (ReaderException const& re) {
+      }
+
+      if (!checkChecksum(tmpResultString)) {
         delete [] endRange;
-				throw re;
+        return Ref<Result>();
-			}
+      }
+
+      Ref<String> resultString(new String(tmpResultString));
+
+      float left = (float) (startGuardRange[1] + startGuardRange[0]) / 2.0f;
+      float right = (float) (endRange[1] + endRange[0]) / 2.0f;
+
+      std::vector< Ref<ResultPoint> > resultPoints(2);
+      Ref<OneDResultPoint> resultPoint1(new OneDResultPoint(left, (float) rowNumber));
+      Ref<OneDResultPoint> resultPoint2(new OneDResultPoint(right, (float) rowNumber));
+      resultPoints[0] = resultPoint1;
+      resultPoints[1] = resultPoint2;
+
+      ArrayRef<unsigned char> resultBytes(1);
+      Ref<Result> res(new Result(resultString, resultBytes, resultPoints, getBarcodeFormat()));
+      delete [] endRange;
+      return res;
     }
 
     int* UPCEANReader::findStartGuardPattern(Ref<BitArray> row) {
       bool foundStart = false;
       int* startRange = NULL;
       int nextStart = 0;
-      try {
+      while (!foundStart) {
-        while (!foundStart) {
-          delete [] startRange;
-          startRange = NULL;
-          startRange = findGuardPattern(row, nextStart, false, START_END_PATTERN,
-              sizeof(START_END_PATTERN) / sizeof(int));
-          int start = startRange[0];
-          nextStart = startRange[1];
-          // Make sure there is a quiet zone at least as big as the start pattern before the barcode.
-          // If this check would run off the left edge of the image, do not accept this barcode,
-          // as it is very likely to be a false positive.
-          int quietStart = start - (nextStart - start);
-          if (quietStart >= 0) {
-            foundStart = row->isRange(quietStart, start, false);
-          }
-        }
-        return startRange;
-      } catch (ReaderException const& re) {
         delete [] startRange;
-        throw re;
+        startRange = findGuardPattern(row, nextStart, false, START_END_PATTERN,
+            sizeof(START_END_PATTERN) / sizeof(int));
+        if (startRange == NULL) {
+          return NULL;
+        }
+        int start = startRange[0];
+        nextStart = startRange[1];
+        // Make sure there is a quiet zone at least as big as the start pattern before the barcode.
+        // If this check would run off the left edge of the image, do not accept this barcode,
+        // as it is very likely to be a false positive.
+        int quietStart = start - (nextStart - start);
+        if (quietStart >= 0) {
+          foundStart = row->isRange(quietStart, start, false);
+        }
       }
+      return startRange;
     }
 
     // TODO(flyashi): Return a pair<int, int> for return value to avoid using the heap.
@@ -225,7 +224,7 @@ namespace zxing {
           isWhite = !isWhite;
         }
       }
-      throw ReaderException("findGuardPattern");
+      return NULL;
     }
 
     int* UPCEANReader::decodeEnd(Ref<BitArray> row, int endStart) {
@@ -236,7 +235,7 @@ namespace zxing {
     int UPCEANReader::decodeDigit(Ref<BitArray> row, int counters[], int countersLen, int rowOffset,
         UPC_EAN_PATTERNS patternType) {
       if (!recordPattern(row, rowOffset, counters, countersLen)) {
-        throw ReaderException("");
+        return -1;
       }
       unsigned int bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept
       int bestMatch = -1;
@@ -278,14 +277,9 @@ namespace zxing {
         default:
           break;
       }
-      if (bestMatch >= 0) {
+      return bestMatch;
-        return bestMatch;
-      } else {
-        throw ReaderException("UPCEANReader::decodeDigit: No best mach");
-      }
     }
 
-
     /**
      * @return {@link #checkStandardUPCEANChecksum(String)}
      */
@@ -299,7 +293,6 @@ namespace zxing {
      *
      * @param s string of digits to check
      * @return true iff string of digits passes the UPC/EAN checksum algorithm
-     * @throws ReaderException if the string does not contain only digits
      */
     bool UPCEANReader::checkStandardUPCEANChecksum(std::string s) {
       int length = s.length();
@@ -311,7 +304,7 @@ namespace zxing {
       for (int i = length - 2; i >= 0; i -= 2) {
         int digit = (int) s[i] - (int) '0';
         if (digit < 0 || digit > 9) {
-          throw ReaderException("checkStandardUPCEANChecksum");
+          return false;
         }
         sum += digit;
       }
@@ -319,7 +312,7 @@ namespace zxing {
       for (int i = length - 1; i >= 0; i -= 2) {
         int digit = (int) s[i] - (int) '0';
         if (digit < 0 || digit > 9) {
-          throw ReaderException("checkStandardUPCEANChecksum");
+          return false;
         }
         sum += digit;
       }

cpp/core/src/zxing/oned/UPCEANReader.h

@@ -20,46 +20,53 @@
  * limitations under the License.
  */
 
-#pragma once
-
 #include <zxing/oned/OneDReader.h>
 #include <zxing/common/BitArray.h>
 #include <zxing/Result.h>
+
 typedef enum UPC_EAN_PATTERNS {
 	UPC_EAN_PATTERNS_L_PATTERNS = 0,
 	UPC_EAN_PATTERNS_L_AND_G_PATTERNS
 } UPC_EAN_PATTERNS;
+
 namespace zxing {
 	namespace oned {
 		class UPCEANReader : public OneDReader {
-			
+
 		private:
 			static const unsigned int MAX_AVG_VARIANCE = (unsigned int) (PATTERN_MATCH_RESULT_SCALE_FACTOR * 0.42f);
 			static const int MAX_INDIVIDUAL_VARIANCE = (int) (PATTERN_MATCH_RESULT_SCALE_FACTOR * 0.7f);
-			
+
-			static int* findStartGuardPattern(Ref<BitArray> row);																	//throws ReaderException
+			static int* findStartGuardPattern(Ref<BitArray> row);
-			
+
-			virtual int* decodeEnd(Ref<BitArray> row, int endStart);																		//throws ReaderException
+			virtual int* decodeEnd(Ref<BitArray> row, int endStart);
-			
+
-			static bool checkStandardUPCEANChecksum(std::string s);																	//throws ReaderException 
+			static bool checkStandardUPCEANChecksum(std::string s);
 		protected:
-			static int* findGuardPattern(Ref<BitArray> row, int rowOffset, bool whiteFirst, const int pattern[], int patternLen);	//throws ReaderException 
+			static int* findGuardPattern(Ref<BitArray> row, int rowOffset, bool whiteFirst,
-			
+			    const int pattern[], int patternLen);
+
 			virtual const int getMIDDLE_PATTERN_LEN();
 			virtual const int* getMIDDLE_PATTERN();
-			
+
 		public:
 			UPCEANReader();
-			
+
-			virtual int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen, std::string& resultString) = 0;			//throws ReaderException
+      // Returns < 0 on failure, >= 0 on success.
-			
+			virtual int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen,
+			    std::string& resultString) = 0;
+
 			Ref<Result> decodeRow(int rowNumber, Ref<BitArray> row);
+
+			// TODO(dswitkin): Should this be virtual so that UPCAReader can override it?
 			Ref<Result> decodeRow(int rowNumber, Ref<BitArray> row, int startGuardRange[]);
-			
+
-			static int decodeDigit(Ref<BitArray> row, int counters[], int countersLen, int rowOffset, UPC_EAN_PATTERNS patternType);	//throws ReaderException 
+      // Returns < 0 on failure, >= 0 on success.
-			
+			static int decodeDigit(Ref<BitArray> row, int counters[], int countersLen, int rowOffset,
-			virtual bool checkChecksum(std::string s);																						//throws ReaderException
+			    UPC_EAN_PATTERNS patternType);
-			
+
+			virtual bool checkChecksum(std::string s);
+
 			virtual BarcodeFormat getBarcodeFormat() = 0;
 			virtual ~UPCEANReader();
 		};

cpp/core/src/zxing/oned/UPCEReader.cpp

@@ -49,12 +49,14 @@ namespace zxing {
 
 			int end = row->getSize();
 			int rowOffset = startRange[1];
-
 			int lgPatternFound = 0;
 
 			for (int x = 0; x < 6 && rowOffset < end; x++) {
 				int bestMatch = decodeDigit(row, counters, countersLen, rowOffset,
 				    UPC_EAN_PATTERNS_L_AND_G_PATTERNS);
+				if (bestMatch < 0) {
+          return -1;
+        }
 				resultString.append(1, (char) ('0' + bestMatch % 10));
 				for (int i = 0; i < countersLen; i++) {
 					rowOffset += counters[i];
@@ -64,8 +66,9 @@ namespace zxing {
 				}
 			}
 
-			determineNumSysAndCheckDigit(resultString, lgPatternFound);
+			if (!determineNumSysAndCheckDigit(resultString, lgPatternFound)) {
-
+        return -1;
+      }
 			return rowOffset;
 		}
 
@@ -79,17 +82,17 @@ namespace zxing {
 		}
 
 
-		void UPCEReader::determineNumSysAndCheckDigit(std::string& resultString, int lgPatternFound) {
+		bool UPCEReader::determineNumSysAndCheckDigit(std::string& resultString, int lgPatternFound) {
 			for (int numSys = 0; numSys <= 1; numSys++) {
 				for (int d = 0; d < 10; d++) {
 					if (lgPatternFound == NUMSYS_AND_CHECK_DIGIT_PATTERNS[numSys][d]) {
 						resultString.insert(0, 1, (char) ('0' + numSys));
 						resultString.append(1, (char) ('0' + d));
-						return;
+						return true;
 					}
 				}
 			}
-			throw ReaderException("determineNumSysAndCheckDigit exception");
+			return false;
 		}
 
 		/**

cpp/core/src/zxing/oned/UPCEReader.h

@@ -26,19 +26,19 @@
 namespace zxing {
 	namespace oned {
 		class UPCEReader : public UPCEANReader {
-			
+
 		private:
-			static void determineFirstDigit(std::string& resultString, int lgPatternFound);								//throws ReaderException
+			static bool determineNumSysAndCheckDigit(std::string& resultString, int lgPatternFound);
-			static void determineNumSysAndCheckDigit(std::string& resultString, int lgPatternFound);						//throws ReaderException
 		protected:
-			int* decodeEnd(Ref<BitArray> row, int endStart);															//throws ReaderException
+			int* decodeEnd(Ref<BitArray> row, int endStart);
-			bool checkChecksum(std::string s);																			//throws ReaderException 
+			bool checkChecksum(std::string s);
 		public:
 			UPCEReader();
-			
+
-			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen, std::string& resultString);		//throws ReaderException
+			int decodeMiddle(Ref<BitArray> row, int startRange[], int startRangeLen,
+			    std::string& resultString);
 			static std::string convertUPCEtoUPCA(std::string upce);
-			
+
 			BarcodeFormat getBarcodeFormat();
 		};
 	}