Commit 4d900d1a authored by Bryce Seager van Dyk's avatar Bryce Seager van Dyk
Browse files

Bug 1673670 - Add vprintf style ctor for nsPrintfCString + tests. r=xpcom-reviewers,sg 

Differential Revision: https://phabricator.services.mozilla.com/D94851
parent 36ba3257

xpcom/string/nsPrintfCString.h

+17 −0
Original line number Diff line number Diff line
@@ -15,6 +15,18 @@ 
 *

 *   NS_WARNING(nsPrintfCString("Unexpected value: %f", 13.917).get());

 *

 * nsPrintfCString also allows for vprintf like calling. This is useful for

 * functions that have already received variadic arguments and want to create

 * a nsPrintfCString. For example:

 *

 * void LogToSeveralLocations(const char* aFormat,...) {

 *   va_list ap;

 *   va_start(ap, aFormat);

 *   nsPrintfCString logString(aFormat, ap);

 *   va_end(ap);

 *   // Use logString

 *  }

 *

 * nsPrintfCString has a small built-in auto-buffer.  For larger strings, it

 * will allocate on the heap.

 *
@@ -31,6 +43,11 @@ class nsPrintfCString : public nsAutoCStringN<16> { 
    AppendPrintf(aFormat, ap);

    va_end(ap);

  }



  nsPrintfCString(const char_type* aFormat, va_list aArgs)

      MOZ_FORMAT_PRINTF(2, 0) {

    AppendPrintf(aFormat, aArgs);

  }

};



#endif  // !defined(nsPrintfCString_h___)

xpcom/tests/gtest/TestStrings.cpp

+64 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <stdio.h>

#include <stdlib.h>

#include "nsASCIIMask.h"

#include "nsPrintfCString.h"

#include "nsString.h"

#include "nsStringBuffer.h"

#include "nsReadableUtils.h"
@@ -1968,6 +1969,69 @@ TEST_F(Strings, ConvertToSpan) { 
  }

}



TEST_F(Strings, printf_string) {

  auto getStringViaVprintfCtor = [](const char* aFormat, ...) {

    // Ensures creation of an nsPrintfCString via the vprintf style ctor.

    va_list ap;

    va_start(ap, aFormat);

    const nsPrintfCString string(aFormat, ap);

    va_end(ap);

    return string;

  };



  {

    const char* format = "Characters %c %%";

    const char* expectedOutput = "Characters B %";

    const nsPrintfCString printfString(format, 'B');

    const nsPrintfCString vprintfString(getStringViaVprintfCtor(format, 'B'));

    EXPECT_TRUE(printfString.Equals(vprintfString))

        << printfString.get() << " != " << vprintfString.get();

    EXPECT_TRUE(printfString.EqualsASCII(expectedOutput))

        << printfString.get() << " != " << expectedOutput;

  }



  {

    const char* format = "Strings %s %s";

    const char* expectedOutput = "Strings foo bar";

    const nsPrintfCString printfString(format, "foo", "bar");

    const nsPrintfCString vprintfString(

        getStringViaVprintfCtor(format, "foo", "bar"));

    EXPECT_TRUE(printfString.Equals(vprintfString))

        << printfString.get() << " != " << vprintfString.get();

    EXPECT_TRUE(printfString.EqualsASCII(expectedOutput))

        << printfString.get() << " != " << expectedOutput;

  }



  {

    const int signedThree = 3;

    const unsigned int unsignedTen = 10;

    const char* format = "Integers %i %.3d %.2u %o %x %X";

    const char* expectedOutput = "Integers 3 003 10 12 a A";

    const nsPrintfCString printfString(format, signedThree, signedThree,

                                       unsignedTen, unsignedTen, unsignedTen,

                                       unsignedTen);

    const nsPrintfCString vprintfString(

        getStringViaVprintfCtor(format, signedThree, signedThree, unsignedTen,

                                unsignedTen, unsignedTen, unsignedTen));

    EXPECT_TRUE(printfString.Equals(vprintfString))

        << printfString.get() << " != " << vprintfString.get();

    EXPECT_TRUE(printfString.EqualsASCII(expectedOutput))

        << printfString.get() << " != " << expectedOutput;

  }



  {

    const char* format = "Floats %f %.0f %e %.2E";

    const char* expectedOutput = "Floats 1.500000 2 1.500000e+00 1.50E+00";

    const nsPrintfCString printfString(format, 1.5, 1.5, 1.5, 1.5);

    const nsPrintfCString vprintfString(

        getStringViaVprintfCtor(format, 1.5, 1.5, 1.5, 1.5));

    EXPECT_TRUE(printfString.Equals(vprintfString))

        << printfString.get() << " != " << vprintfString.get();

    EXPECT_TRUE(printfString.EqualsASCII(expectedOutput))

        << printfString.get() << " != " << expectedOutput;

  }

}



// Note the five calls in the loop, so divide by 100k

MOZ_GTEST_BENCH_F(Strings, PerfStripWhitespace, [this] {

  nsCString test1(mExample1Utf8);