xds: float LRU cache across interceptors #11992
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| return; | ||
| } | ||
| LinkedHashMap<K, V> newCache = createEvictingMap(newSize); | ||
| newCache.putAll(cache); |
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Because maxSize is only updated after the map is created, this map will contain all the entries from cache.
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createEvictingMap is creating an empty LinkedHashMap. There are separator constructors
LinkedHashMap(int initialCapacity, float loadFactor, boolean accessOrder)
LinkedHashMap(Map<? extends K,? extends V> m)
but none that both take an old map and specify the initialCapacity.
| return; | ||
| } | ||
| LinkedHashMap<K, V> newCache = createEvictingMap(newSize); | ||
| newCache.putAll(cache); |
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createEvictingMap is creating an empty LinkedHashMap. There are separator constructors
LinkedHashMap(int initialCapacity, float loadFactor, boolean accessOrder)
LinkedHashMap(Map<? extends K,? extends V> m)
but none that both take an old map and specify the initialCapacity.
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| V getOrInsert(K key, Function<K, V> create) { | ||
| return cache.computeIfAbsent(key, create); | ||
| } | ||
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| private void resizeCache(int newSize) { | ||
| if (newSize >= maxSize) { |
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Can't understand this. I thought if you get a bigger new size you should resize, and if you get an equal or smaller new size only that should be a no-op because decreasing cache size doesn't make since when another filter instance created a bigger cache.
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I agree with your point but well, cache_size is configuration coming externally. We should adhere to the configuration. If the cache size decreases, then we can't use the normal code to discard entries, as that only discards a single entry. So without special code, the configuration wouldn't be observed.
It is generally really bad to not observe configuration updates, from a testing/debugging perspective. You do a config push and see behavior X, but then after restarting you see behavior Y. It can be really hard to track down the bugs.
The cache size doesn't change often, so the performance hit would be temporary (although there are still issues with that). It's also much easier to figure out what happened. If you keep the old cache, then someone may be debugging something and it matters what happened a month ago.
I discussed this with Eric offline on the similar lines and understood this POV.
| static final class Provider implements Filter.Provider { | ||
| long cacheSize = 10; |
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Why are you making a long constant to always cast it to int?
Oh, you've deleted the default in parseFilterConfig(). No, no. parseFilterConfig() should not have any side-effects. The default is 10, not "whatever the last cache size was."
| static final class Provider implements Filter.Provider { | ||
| long cacheSize = 10; |
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private final?
(I see now that you are modifying it. No, it must not be modified.)
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