Prune least valuable cache entries first

• Component: Page Loading
• Status: RESOLVED FIXED

[Antti Koivisto]

Estimat entry value based on its age and access time.

[Antti Koivisto]

Created attachment 248910 [details]
patch

[Antti Koivisto]

Created attachment 248913 [details]
patch

[Darin Adler]

Comment on attachment 248913 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=248913&action=review

> Source/WebKit2/NetworkProcess/cache/NetworkCacheFileSystemPosix.h:87
> +    auto times = fileTimes(path);

It’s a little bit irritating that this function calls fileSystemRepresentation on the path twice, allocating two separate C strings.

> Source/WebKit2/NetworkProcess/cache/NetworkCacheStorage.cpp:312
> +                auto entry = decodeEntry(fileData, channel->fileDescriptor(), read.key);

Is there something that guarantees that the file descriptor is still open at this point? Just extending the lifetime of the IOChannel alone doesn’t seem to guarantee that.

> Source/WebKit2/NetworkProcess/cache/NetworkCacheStorage.cpp:592
> +    if (age <= seconds::zero() || accessAge > age)
> +        return maximumProbability;

No check for accessAge < 0?

[Antti Koivisto]

Comment on attachment 248913 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=248913&action=review

>> Source/WebKit2/NetworkProcess/cache/NetworkCacheStorage.cpp:312
>> +                auto entry = decodeEntry(fileData, channel->fileDescriptor(), read.key);
> 
> Is there something that guarantees that the file descriptor is still open at this point? Just extending the lifetime of the IOChannel alone doesn’t seem to guarantee that.

It should, slightly indirectly. File closes when the underlying dispatch_io closes and IOChannel refs it:

m_dispatchIO = adoptDispatch(dispatch_io_create(DISPATCH_IO_RANDOM, fd, dispatch_get_main_queue(), [fd](int) {
        close(fd);
 }));

[Chris Dumez]

Comment on attachment 248913 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=248913&action=review

> Source/WebKit2/ChangeLog:5
> +

<rdar://problem/19632130>

> Source/WebKit2/NetworkProcess/cache/NetworkCacheStorage.cpp:292
> +    // We update access time

nit: Missing period at the end.

[Antti Koivisto]

https://trac.webkit.org/r181700