Source/core/css/resolver/StyleResolverStats.cpp

/*
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#include "config.h"
#include "core/css/resolver/StyleResolverStats.h"

#include "wtf/text/CString.h"
#include "wtf/text/StringBuilder.h"

#define PERCENT(x, y) ((!y) ? 0 : (((x) * 100.0) / (y)))

namespace blink {

void StyleResolverStats::reset()
{
    sharedStyleLookups = 0;
    sharedStyleCandidates = 0;
    sharedStyleFound = 0;
    sharedStyleMissed = 0;
    sharedStyleRejectedByUncommonAttributeRules = 0;
    sharedStyleRejectedBySiblingRules = 0;
    sharedStyleRejectedByParent = 0;
    matchedPropertyApply = 0;
    matchedPropertyCacheHit = 0;
    matchedPropertyCacheInheritedHit = 0;
    matchedPropertyCacheAdded = 0;
}

String StyleResolverStats::report() const
{
    StringBuilder output;

    unsigned sharedStylesRejected = sharedStyleRejectedByUncommonAttributeRules + sharedStyleRejectedBySiblingRules + sharedStyleRejectedByParent;
    unsigned sharedStylesUsed = sharedStyleFound - sharedStylesRejected;

    output.append("Style sharing:\n");
    output.append(String::format("  %u elements were added to the sharing candidate list.\n", sharedStyleCandidates));
    output.append(String::format("  %u calls were made to findSharedStyle, %u found a candidate to share with (%.2f%%).\n", sharedStyleLookups, sharedStyleFound, PERCENT(sharedStyleFound, sharedStyleLookups)));
    if (printMissedCandidateCount)
        output.append(String::format("  %u candidates could have matched but were not in the list when searching (%.2f%%).\n", sharedStyleMissed, PERCENT(sharedStyleMissed, sharedStyleLookups)));
    output.append(String::format("  %u of found styles were rejected (%.2f%%), %.2f%% by uncommon attribute rules, %.2f%% by sibling rules and %.2f%% by parents disabling sharing.\n",
        sharedStylesRejected,
        PERCENT(sharedStylesRejected, sharedStyleFound),
        PERCENT(sharedStyleRejectedByUncommonAttributeRules, sharedStylesRejected),
        PERCENT(sharedStyleRejectedBySiblingRules, sharedStylesRejected),
        PERCENT(sharedStyleRejectedByParent, sharedStylesRejected)));
    output.append(String::format("  %u of found styles were used for sharing (%.2f%%).\n", sharedStylesUsed, PERCENT(sharedStylesUsed, sharedStyleFound)));
    output.append(String::format("  %.2f%% of calls to findSharedStyle returned a shared style.\n", PERCENT(sharedStylesUsed, sharedStyleLookups)));

    output.append("\n");

    output.append("Matched property cache:\n");
    output.append(String::format("  %u calls to applyMatchedProperties, %u hit the cache (%.2f%%).\n", matchedPropertyApply, matchedPropertyCacheHit, PERCENT(matchedPropertyCacheHit, matchedPropertyApply)));
    output.append(String::format("  %u cache hits also shared the inherited style (%.2f%%).\n", matchedPropertyCacheInheritedHit, PERCENT(matchedPropertyCacheInheritedHit, matchedPropertyCacheHit)));
    output.append(String::format("  %u styles created in applyMatchedProperties were added to the cache (%.2f%%).\n", matchedPropertyCacheAdded, PERCENT(matchedPropertyCacheAdded, matchedPropertyApply)));

    return output.toString();
}

} // namespace blink