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Windows timestamp in converter panel #114

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Windows timestamp in converter panel #114

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d5d171d
added windows timestamp in converter panel
sealmove Apr 21, 2020
df2bcc0
changed 'int' to 'number'
sealmove Apr 22, 2020
139ccb1
changed naming convention for the newly added Windows FILETIME timestamp
sealmove Apr 22, 2020
bbb8b88
changed 'filets' to 'filetime'
sealmove Jul 4, 2020
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3 changes: 2 additions & 1 deletion src/ui/Components/ConverterPanel.html
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Original file line number Diff line number Diff line change
Expand Up @@ -21,10 +21,11 @@
<tr><td>float</td> <td colspan="2">{{model.float }}</td></tr>
<tr><td>double</td> <td colspan="2">{{model.double}}</td></tr>
<tr><td>unixts</td> <td colspan="2">{{model.unixts}}</td></tr>
<tr><td>filetime</td> <td colspan="2">{{model.filetime}}</td></tr>
<tr><td>ascii</td> <td colspan="2"><div class="str">{{model.ascii }}</div></td></tr>
<tr><td>utf8</td> <td colspan="2"><div class="str">{{model.utf8 }}</div></td></tr>
<tr><td>utf16le</td><td colspan="2"><div class="str">{{model.utf16le}}</div></td></tr>
<tr><td>utf16be</td><td colspan="2"><div class="str">{{model.utf16be}}</div></td></tr>
</table>
</div>
</template>
</template>
12 changes: 12 additions & 0 deletions src/ui/Components/ConverterPanel.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,14 @@ export class Converter {
return str.substring(0, i);
return str + "...";
}

static fileToUnixTime(filetime: number): number {
var unixEpoch = new Date(1970, 1, 1).getTime()
var filetimeEpoch = new Date(1601, 1, 1).getTime()
var epochDeltaInSec = (unixEpoch - filetimeEpoch) / 1_000
var filetimeInSec = filetime / 10_000_000
return filetimeInSec - epochDeltaInSec
}
}

export class ConverterPanelModel {
Expand All @@ -48,6 +56,7 @@ export class ConverterPanelModel {
float: string = "";
double: string = "";
unixts: string = "";
filetime: string = "";
ascii: string = "";
utf8: string = "";
utf16le: string = "";
Expand Down Expand Up @@ -75,6 +84,9 @@ export class ConverterPanelModel {
var u32le = Converter.numConv(data, 4, false, false);
this.unixts = u32le ? dateFormat(new Date(parseInt(u32le) * 1000), "yyyy-mm-dd HH:MM:ss") : "";

var u64le = Converter.numConv(data, 8, false, false);
this.filetime = u64le ? dateFormat(new Date(Converter.fileToUnixTime(parseInt(u64le)) * 1000), "yyyy-mm-dd HH:MM:ss") : "";
Comment on lines +87 to +88
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@generalmimon generalmimon Jul 4, 2020 •
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@sealmove Unfonutately, as all numbers in JavaScript are doubles with just 53 bits of mantissa, a 64-bit integer will lose precision during the conversion to it (using the parseInt method). It means that not all integers larger than 253 - 1 (available in the Number.MAX_SAFE_INTEGER constant) can't be represented accurately in the native JavaScript number type: e.g. Number.MAX_SAFE_INTEGER + 1 == Number.MAX_SAFE_INTEGER + 2, see MDN.

But it doesn't have to happen here, because the Converter.numConv method works internally with a bigInt, though it returns a string (don't know why). Anyway, I would suggest to convert the string to the bigInt type, and do the arithmetics you need to do in the fileToUnixTime method using its methods instead of the native arithmetic operators.

And I just checked that Date object has more than sufficient range for not losing precision here, it's even far larger than FILETIME has (maximum year in FILETIME is ~30828, maximum year of Date is 275760), so there shouldn't be a problem, if you choose a safe method of initializing it.

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there shouldn't be a problem, if you choose a safe method of initializing it.

@sealmove Actually, you can safely ignore that "safe method". I've just tested on RunKit the maximum year 30828 of FILETIME, and the number that represents that Date (number of milliseconds that have elapsed since midnight on January 1, 1970, UTC) is still ~10 times less than the Number.MAX_SAFE_INTEGER, so it will be fine to just stuff that Unix timestamp * 1000 number into the new Date() constructor, after you do the arithmetic with bigInt.


try {
this.ascii = Converter.strDecode(data, "ascii");
this.utf8 = Converter.strDecode(data, "utf-8");
Expand Down