]> git.ipfire.org Git - thirdparty/squid.git/blame - src/MemStore.h
Do not allow broken IpcIo-based cache_dir to be selected for swap out.
[thirdparty/squid.git] / src / MemStore.h
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1#ifndef SQUID_MEMSTORE_H
2#define SQUID_MEMSTORE_H
3
68353d5a 4#include "ipc/mem/Page.h"
06684a9b 5#include "ipc/mem/PageStack.h"
68353d5a 6#include "ipc/StoreMap.h"
9487bae9 7#include "Store.h"
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8
9// StoreEntry restoration info not already stored by Ipc::StoreMap
10struct MemStoreMapExtras {
06684a9b 11 Ipc::Mem::PageId page; ///< shared memory page with the slice content
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12};
13typedef Ipc::StoreMapWithExtras<MemStoreMapExtras> MemStoreMap;
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14
15/// Stores HTTP entities in RAM. Current implementation uses shared memory.
16/// Unlike a disk store (SwapDir), operations are synchronous (and fast).
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17class MemStore: public Store, public Ipc::StoreMapCleaner
18{
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19public:
20 MemStore();
21 virtual ~MemStore();
22
23 /// cache the entry or forget about it until the next considerKeeping call
24 void considerKeeping(StoreEntry &e);
25
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26 /// whether e should be kept in local RAM for possible future caching
27 bool keepInLocalMemory(const StoreEntry &e) const;
28
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29 /* Store API */
30 virtual int callback();
31 virtual StoreEntry * get(const cache_key *);
32 virtual void get(String const key , STOREGETCLIENT callback, void *cbdata);
33 virtual void init();
34 virtual uint64_t maxSize() const;
35 virtual uint64_t minSize() const;
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36 virtual uint64_t currentSize() const;
37 virtual uint64_t currentCount() const;
af2fda07 38 virtual int64_t maxObjectSize() const;
93bc1434 39 virtual void getStats(StoreInfoStats &stats) const;
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40 virtual void stat(StoreEntry &) const;
41 virtual StoreSearch *search(String const url, HttpRequest *);
42 virtual void reference(StoreEntry &);
54347cbd 43 virtual bool dereference(StoreEntry &, bool);
9487bae9 44 virtual void maintain();
9487bae9 45
68353d5a 46 static int64_t EntryLimit();
a4555399 47
9487bae9 48protected:
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49 void keep(StoreEntry &e);
50
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51 bool copyToShm(StoreEntry &e, const sfileno index, Ipc::StoreMapAnchor &anchor);
52 bool copyToShmSlice(StoreEntry &e, const sfileno index, Ipc::StoreMapAnchor &anchor, int64_t &offset);
53 bool copyFromShm(StoreEntry &e, const sfileno index, const Ipc::StoreMapAnchor &anchor);
54 bool copyFromShmSlice(StoreEntry &e, StoreIOBuffer &buf, bool eof);
55
56 sfileno reserveSapForWriting(Ipc::Mem::PageId &page);
9487bae9 57
7f6748c8 58 // Ipc::StoreMapCleaner API
10dc0fe6 59 virtual void noteFreeMapSlice(const sfileno sliceId);
7f6748c8 60
9487bae9 61private:
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62 // TODO: move freeSlots into map
63 Ipc::Mem::Pointer<Ipc::Mem::PageStack> freeSlots; ///< unused map slot IDs
9487bae9 64 MemStoreMap *map; ///< index of mem-cached entries
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65
66 /// the last allocate slice for writing a store entry (during copyToShm)
67 sfileno lastWritingSlice;
68
69 /// temporary storage for slot and page ID pointers; for the waiting cache
70 class SlotAndPage {
71 public:
72 SlotAndPage(): slot(NULL), page(NULL) {}
73 bool operator !() const { return !slot && !page; }
74 Ipc::Mem::PageId *slot; ///< local slot variable, waiting to be filled
75 Ipc::Mem::PageId *page; ///< local page variable, waiting to be filled
76 };
77 SlotAndPage waitingFor; ///< a cache for a single "hot" free slot and page
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78};
79
80// Why use Store as a base? MemStore and SwapDir are both "caches".
81
82// Why not just use a SwapDir API? That would not help much because Store has
83// to check/update memory cache separately from the disk cache. And same API
84// would hurt because we can support synchronous get/put, unlike the disks.
85
86#endif /* SQUID_MEMSTORE_H */