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use simplified hash function to ensure same result on any platform

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This commit is contained in:
john30
2017-04-17 14:28:33 +02:00
parent f2dd0ffd25
commit aaea8f72ab
2 changed files with 10 additions and 5 deletions
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src/lib/ebus/filereader.cpp
+8 -3
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@@ -118,7 +118,13 @@ void FileReader::tolower(string& str) {
transform(str.begin(), str.end(), str.begin(), ::tolower);
}
static std::hash<string> hashFunction;
static size_t hashFunction(const string str) {
size_t hash = 0;
for (char c : str) {
hash = (31 * hash) ^ c;
}
return hash;
}
bool FileReader::splitFields(istream& ifs, vector<string>& row, unsigned int& lineNo,
size_t* hash, size_t* size) {
@@ -137,8 +143,7 @@ bool FileReader::splitFields(istream& ifs, vector<string>& row, unsigned int& li
*size += length + 1; // normalized with trailing endl
}
if (hash) {
// TODO ensure 32 bit machine produces same result
*hash ^= (hashFunction(line) << 1) ^ (length << (7 * (lineNo % 5)));
*hash ^= (hashFunction(line) ^ (length << (7 * (lineNo % 5)))) & 0xffffffff;
}
if (!quotedText && (length == 0 || line[0] == '#' || (line.length() > 1 && line[0] == '/' && line[1] == '/'))) {
if (lineNo == 1) {