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rewrite parseIntegerList with better performance #19619

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Merged
merged 1 commit into from
Apr 19, 2019
Merged

rewrite parseIntegerList with better performance #19619

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29 changes: 13 additions & 16 deletions cocos/2d/CCSpriteFrameCache.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -79,23 +79,20 @@ SpriteFrameCache::~SpriteFrameCache()

void SpriteFrameCache::parseIntegerList(const std::string &string, std::vector<int> &res)
{
std::string delim(" ");

size_t n = std::count(string.begin(), string.end(), ' ');
res.resize(n+1);

size_t start = 0U;
size_t end = string.find(delim);

int i=0;
while (end != std::string::npos)
{
res[i++] = atoi(string.substr(start, end - start).c_str());
start = end + delim.length();
end = string.find(delim, start);
}

res[i] = atoi(string.substr(start, end).c_str());
res.resize(n + 1);

const char *cStr = string.c_str();
char *endptr;

int i = 0;
do {
long int val = strtol(cStr, &endptr, 10);
if (endptr == cStr)
return;
res[i++] = static_cast<int>(val);
cStr = endptr;
} while (*endptr != '\0');
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There are two conditions to terminate the while loop:

  • endptr == cStr
  • *endptr == '\0'

Does it need tow conditions?
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I am not sure about the precondition of the string containing list of integers. I added it because I am not sure about the string format.

Does the plist file guarantee that the string is a list of integers separated by a single space? If so, the endptr == cStr statement is redundant. It can be deleted safely.

However, if the string could be like " " (a string with a single space), this loop will run forever without the above condition. A plist file with wrong format may cause the program hang on.

Or the file have been sanitized somewhere else?
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K, then i think keep it is more safe.
}

void SpriteFrameCache::initializePolygonInfo(const Size &textureSize,
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