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TerraSync: Rate-limit hash-cache writes

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This helps with IO-limited performance on Windows
This commit is contained in:
Automatic Release Builder 2020-10-07 12:23:33 +01:00
parent 05094510be
commit 9c530d6978
1 changed files with 13 additions and 8 deletions
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21
simgear/io/HTTPRepository.cxx
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@ -111,7 +111,7 @@ public:
typedef std::vector<HashCacheEntry> HashCache; typedef std::vector<HashCacheEntry> HashCache;
HashCache hashes; HashCache hashes;
bool hashCacheDirty; int hashCacheDirty = 0;
struct Failure struct Failure
{ {
@ -123,7 +123,6 @@ public:
FailureList failures; FailureList failures;
HTTPRepoPrivate(HTTPRepository* parent) : HTTPRepoPrivate(HTTPRepository* parent) :
hashCacheDirty(false),
p(parent), p(parent),
isUpdating(false), isUpdating(false),
status(HTTPRepository::REPO_NO_ERROR), status(HTTPRepository::REPO_NO_ERROR),
@ -1083,10 +1082,10 @@ HTTPRepository::failure() const
void HTTPRepoPrivate::updatedFileContents(const SGPath& p, const std::string& newHash) void HTTPRepoPrivate::updatedFileContents(const SGPath& p, const std::string& newHash)
{ {
// remove the existing entry // remove the existing entry
HashCache::iterator it = std::find_if(hashes.begin(), hashes.end(), HashEntryWithPath(p)); auto it = std::find_if(hashes.begin(), hashes.end(), HashEntryWithPath(p));
if (it != hashes.end()) { if (it != hashes.end()) {
hashes.erase(it); hashes.erase(it);
hashCacheDirty = true; ++hashCacheDirty;
} }
if (newHash.empty()) { if (newHash.empty()) {
@ -1105,12 +1104,12 @@ HTTPRepository::failure() const
entry.lengthBytes = p2.sizeInBytes(); entry.lengthBytes = p2.sizeInBytes();
hashes.push_back(entry); hashes.push_back(entry);
hashCacheDirty = true; ++hashCacheDirty ;
} }
void HTTPRepoPrivate::writeHashCache() void HTTPRepoPrivate::writeHashCache()
{ {
if (!hashCacheDirty) { if (hashCacheDirty == 0) {
return; return;
} }
@ -1123,7 +1122,7 @@ HTTPRepository::failure() const
<< it->lengthBytes << "*" << it->hashHex << "\n"; << it->lengthBytes << "*" << it->hashHex << "\n";
} }
stream.close(); stream.close();
hashCacheDirty = false; hashCacheDirty = 0;
} }
void HTTPRepoPrivate::parseHashCache() void HTTPRepoPrivate::parseHashCache()
@ -1237,10 +1236,16 @@ HTTPRepository::failure() const
http->makeRequest(rr); http->makeRequest(rr);
} }
writeHashCache(); // rate limit how often we write this, since otherwise
// it dominates the time on Windows. 256 seems about right,
// causes a write a few times a minute.
if (hashCacheDirty > 256) {
writeHashCache();
}
if (activeRequests.empty() && queuedRequests.empty()) { if (activeRequests.empty() && queuedRequests.empty()) {
isUpdating = false; isUpdating = false;
writeHashCache();
} }
} }