Return error if precision or exponent of numbers are larger than we s…

…upport. Fixes #127. (See also related issue #128)
SBJson · Mar 21, 2012 · b95c5b6 · b95c5b6
1 parent 4bc6ae1
commit b95c5b6
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Showing 9 changed files with 43 additions and 17 deletions.
diff --git a/Classes/SBJsonTokeniser.m b/Classes/SBJsonTokeniser.m
@@ -36,11 +36,22 @@
 #define SBStringIsSurrogateLowCharacter(character) ((character >= 0xDC00UL) && (character <= 0xDFFFUL))
 #define SBStringIsSurrogateHighCharacter(character) ((character >= 0xD800UL) && (character <= 0xDBFFUL))
 
+static int const DECIMAL_MAX_PRECISION = 38;
+static int const DECIMAL_EXPONENT_MAX = 127;
+static short const DECIMAL_EXPONENT_MIN = -128;
+static int const LONG_LONG_DIGITS = 20;
+
+static NSCharacterSet *kDecimalDigitCharacterSet;
+
 @implementation SBJsonTokeniser
 
 @synthesize error = _error;
 @synthesize stream = _stream;
 
++ (void)initialize {
+    kDecimalDigitCharacterSet = [NSCharacterSet decimalDigitCharacterSet];
+}
+
 - (id)init {
     self = [super init];
     if (self) {
@@ -241,7 +252,6 @@ - (sbjson_token_t)getStringToken:(NSObject**)token {
 - (sbjson_token_t)getNumberToken:(NSObject**)token {
 
     NSUInteger numberStart = _stream.index;
-    NSCharacterSet *digits = [NSCharacterSet decimalDigitCharacterSet];
 
     unichar ch;
     if (![_stream getUnichar:&ch])
@@ -262,13 +272,13 @@ - (sbjson_token_t)getNumberToken:(NSObject**)token {
         if (![_stream getNextUnichar:&ch])
             return sbjson_token_eof;
 
-        if ([digits characterIsMember:ch]) {
+        if ([kDecimalDigitCharacterSet characterIsMember:ch]) {
             self.error = @"Leading zero is illegal in number";
             return sbjson_token_error;
         }
     }
 
-    while ([digits characterIsMember:ch]) {
+    while ([kDecimalDigitCharacterSet characterIsMember:ch]) {
         mantissa *= 10;
         mantissa += (ch - '0');
         mantissa_length++;
@@ -285,7 +295,7 @@ - (sbjson_token_t)getNumberToken:(NSObject**)token {
         if (![_stream getNextUnichar:&ch])
             return sbjson_token_eof;
 
-        while ([digits characterIsMember:ch]) {
+        while ([kDecimalDigitCharacterSet characterIsMember:ch]) {
             mantissa *= 10;
             mantissa += (ch - '0');
             mantissa_length++;
@@ -321,7 +331,7 @@ - (sbjson_token_t)getNumberToken:(NSObject**)token {
 
         short explicit_exponent = 0;
         short explicit_exponent_length = 0;
-        while ([digits characterIsMember:ch]) {
+        while ([kDecimalDigitCharacterSet characterIsMember:ch]) {
             explicit_exponent *= 10;
             explicit_exponent += (ch - '0');
             explicit_exponent_length++;
@@ -345,20 +355,29 @@ - (sbjson_token_t)getNumberToken:(NSObject**)token {
         self.error = @"No digits after initial minus";
         return sbjson_token_error;
 
-    } else if (mantissa_length >= 19) {
-
+    } else if (mantissa_length > DECIMAL_MAX_PRECISION) {
+        self.error = @"Precision is too high";
+        return sbjson_token_error;
+
+    } else if (exponent > DECIMAL_EXPONENT_MAX || exponent < DECIMAL_EXPONENT_MIN) {
+        self.error = @"Exponent out of range";
+        return sbjson_token_error;
+    }
+
+    if (mantissa_length <= LONG_LONG_DIGITS) {
+        if (!isFloat && !hasExponent) {
+            *token = [NSNumber numberWithLongLong: isNegative ? -mantissa : mantissa];
+
+        } else {
+            *token = [NSDecimalNumber decimalNumberWithMantissa:mantissa
+                                                       exponent:exponent
+                                                     isNegative:isNegative];
+        }
+
+    } else {
         NSString *number = [_stream stringWithRange:NSMakeRange(numberStart, _stream.index - numberStart)];
         *token = [NSDecimalNumber decimalNumberWithString:number];
 
-    } else if (!isFloat && !hasExponent) {
-        if (!isNegative)
-            *token = [NSNumber numberWithUnsignedLongLong:mantissa];
-        else
-            *token = [NSNumber numberWithLongLong:-mantissa];
-    } else {
-        *token = [NSDecimalNumber decimalNumberWithMantissa:mantissa
-                                                   exponent:exponent
-                                                 isNegative:isNegative];
     }
 
     return sbjson_token_number;

diff --git a/NEWS.md b/NEWS.md
@@ -17,6 +17,7 @@ Miscellaneous
 * Added an optional comparator that is used when sorting keys.
 * Be more memory-efficient when parsing long strings containing escaped characters.
 * Add a Workspace that includes the sample projects, for ease of browsing.
+* Report error for numbers with exponents outside range of -128 to 127.
 
 
 3.0 (June 18th, 2011)

diff --git a/Tests/Data/invalid/number/overflow-exponent-1/error b/Tests/Data/invalid/number/overflow-exponent-1/error
@@ -0,0 +1 @@
+Exponent out of range
diff --git a/Tests/Data/invalid/number/overflow-exponent-1/input b/Tests/Data/invalid/number/overflow-exponent-1/input
@@ -0,0 +1 @@
+[1e128]
diff --git a/Tests/Data/invalid/number/overflow-exponent-2/error b/Tests/Data/invalid/number/overflow-exponent-2/error
@@ -0,0 +1 @@
+Exponent out of range
diff --git a/Tests/Data/invalid/number/overflow-exponent-2/input b/Tests/Data/invalid/number/overflow-exponent-2/input
@@ -0,0 +1 @@
+[1e-129]
diff --git a/Tests/Data/invalid/number/overflow-mantissa/error b/Tests/Data/invalid/number/overflow-mantissa/error
@@ -0,0 +1 @@
+Precision is too high
diff --git a/Tests/Data/invalid/number/overflow-mantissa/input b/Tests/Data/invalid/number/overflow-mantissa/input
@@ -0,0 +1 @@
+[123456789012345678901234567890123456789]
diff --git a/Tests/ErrorTest.m b/Tests/ErrorTest.m
@@ -67,7 +67,7 @@ - (void)testData {
 
     }];
 
-    STAssertEquals(count, (NSUInteger)28, nil);
+    STAssertEquals(count, (NSUInteger)31, nil);
 }
 
 - (void)testWriteRecursion {