mfbt/double-conversion/bignum-dtoa.h@97036ab72558 (annotated)
mfbt/double-conversion/bignum-dtoa.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | // Copyright 2010 the V8 project authors. All rights reserved. |
| michael@0 | 2 | // Redistribution and use in source and binary forms, with or without |
| michael@0 | 3 | // modification, are permitted provided that the following conditions are |
| michael@0 | 4 | // met: |
| michael@0 | 5 | // |
| michael@0 | 6 | // * Redistributions of source code must retain the above copyright |
| michael@0 | 7 | // notice, this list of conditions and the following disclaimer. |
| michael@0 | 8 | // * Redistributions in binary form must reproduce the above |
| michael@0 | 9 | // copyright notice, this list of conditions and the following |
| michael@0 | 10 | // disclaimer in the documentation and/or other materials provided |
| michael@0 | 11 | // with the distribution. |
| michael@0 | 12 | // * Neither the name of Google Inc. nor the names of its |
| michael@0 | 13 | // contributors may be used to endorse or promote products derived |
| michael@0 | 14 | // from this software without specific prior written permission. |
| michael@0 | 15 | // |
| michael@0 | 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| michael@0 | 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| michael@0 | 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| michael@0 | 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| michael@0 | 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| michael@0 | 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| michael@0 | 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| michael@0 | 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| michael@0 | 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| michael@0 | 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| michael@0 | 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| michael@0 | 27 | |
| michael@0 | 28 | #ifndef DOUBLE_CONVERSION_BIGNUM_DTOA_H_ |
| michael@0 | 29 | #define DOUBLE_CONVERSION_BIGNUM_DTOA_H_ |
| michael@0 | 30 | |
| michael@0 | 31 | #include "utils.h" |
| michael@0 | 32 | |
| michael@0 | 33 | namespace double_conversion { |
| michael@0 | 34 | |
| michael@0 | 35 | enum BignumDtoaMode { |
| michael@0 | 36 | // Return the shortest correct representation. |
| michael@0 | 37 | // For example the output of 0.299999999999999988897 is (the less accurate but |
| michael@0 | 38 | // correct) 0.3. |
| michael@0 | 39 | BIGNUM_DTOA_SHORTEST, |
| michael@0 | 40 | // Same as BIGNUM_DTOA_SHORTEST but for single-precision floats. |
| michael@0 | 41 | BIGNUM_DTOA_SHORTEST_SINGLE, |
| michael@0 | 42 | // Return a fixed number of digits after the decimal point. |
| michael@0 | 43 | // For instance fixed(0.1, 4) becomes 0.1000 |
| michael@0 | 44 | // If the input number is big, the output will be big. |
| michael@0 | 45 | BIGNUM_DTOA_FIXED, |
| michael@0 | 46 | // Return a fixed number of digits, no matter what the exponent is. |
| michael@0 | 47 | BIGNUM_DTOA_PRECISION |
| michael@0 | 48 | }; |
| michael@0 | 49 | |
| michael@0 | 50 | // Converts the given double 'v' to ascii. |
| michael@0 | 51 | // The result should be interpreted as buffer * 10^(point-length). |
| michael@0 | 52 | // The buffer will be null-terminated. |
| michael@0 | 53 | // |
| michael@0 | 54 | // The input v must be > 0 and different from NaN, and Infinity. |
| michael@0 | 55 | // |
| michael@0 | 56 | // The output depends on the given mode: |
| michael@0 | 57 | // - SHORTEST: produce the least amount of digits for which the internal |
| michael@0 | 58 | // identity requirement is still satisfied. If the digits are printed |
| michael@0 | 59 | // (together with the correct exponent) then reading this number will give |
| michael@0 | 60 | // 'v' again. The buffer will choose the representation that is closest to |
| michael@0 | 61 | // 'v'. If there are two at the same distance, than the number is round up. |
| michael@0 | 62 | // In this mode the 'requested_digits' parameter is ignored. |
| michael@0 | 63 | // - FIXED: produces digits necessary to print a given number with |
| michael@0 | 64 | // 'requested_digits' digits after the decimal point. The produced digits |
| michael@0 | 65 | // might be too short in which case the caller has to fill the gaps with '0's. |
| michael@0 | 66 | // Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2. |
| michael@0 | 67 | // Halfway cases are rounded up. The call toFixed(0.15, 2) thus returns |
| michael@0 | 68 | // buffer="2", point=0. |
| michael@0 | 69 | // Note: the length of the returned buffer has no meaning wrt the significance |
| michael@0 | 70 | // of its digits. That is, just because it contains '0's does not mean that |
| michael@0 | 71 | // any other digit would not satisfy the internal identity requirement. |
| michael@0 | 72 | // - PRECISION: produces 'requested_digits' where the first digit is not '0'. |
| michael@0 | 73 | // Even though the length of produced digits usually equals |
| michael@0 | 74 | // 'requested_digits', the function is allowed to return fewer digits, in |
| michael@0 | 75 | // which case the caller has to fill the missing digits with '0's. |
| michael@0 | 76 | // Halfway cases are again rounded up. |
| michael@0 | 77 | // 'BignumDtoa' expects the given buffer to be big enough to hold all digits |
| michael@0 | 78 | // and a terminating null-character. |
| michael@0 | 79 | void BignumDtoa(double v, BignumDtoaMode mode, int requested_digits, |
| michael@0 | 80 | Vector<char> buffer, int* length, int* point); |
| michael@0 | 81 | |
| michael@0 | 82 | } // namespace double_conversion |
| michael@0 | 83 | |
| michael@0 | 84 | #endif // DOUBLE_CONVERSION_BIGNUM_DTOA_H_ |
