PeerDigest.h

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/*
 * Copyright (C) 1996-2026 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */
 
#ifndef SQUID_SRC_PEERDIGEST_H
#define SQUID_SRC_PEERDIGEST_H
 
#if USE_CACHE_DIGESTS
 
#include "cbdata.h"
#include "StatCounters.h"
 
class Version
{
public:
    short int current;      /* current version */
    short int required;     /* minimal version that can safely handle current version */
};
 
/* digest control block; used for transmission and storage */
 
class StoreDigestCBlock
{
public:
    Version ver;
    int capacity;
    int count;
    int del_count;
    int mask_size;
    unsigned char bits_per_entry;
    unsigned char hash_func_count;
    short int reserved_short;
    int reserved[32 - 6];
};
 
class HttpRequest;
class PeerDigest;
class store_client;
 
class DigestFetchState
{
    CBDATA_CLASS(DigestFetchState);
 
public:
    DigestFetchState(PeerDigest *,HttpRequest *);
    ~DigestFetchState();
 
    CbcPointer<PeerDigest> pd;
    StoreEntry *entry;
    StoreEntry *old_entry;
    store_client *sc;
    store_client *old_sc;
    HttpRequest *request;
    int offset;
    uint32_t mask_offset;
    time_t start_time;
    time_t resp_time;
    time_t expires;
 
    struct {
        int msg;
        int bytes;
    } sent, recv;
 
    char buf[SM_PAGE_SIZE];
    ssize_t bufofs;
    digest_read_state_t state;
};
 
class PeerDigest
{
    CBDATA_CLASS(PeerDigest);
 
public:
    PeerDigest(CachePeer *);
    ~PeerDigest();
 
    void noteFetchFinished(const DigestFetchState &, const char *outcomeDescription, bool sawError);
 
    CbcPointer<CachePeer> peer; 
    CacheDigest *cd = nullptr;            
    const SBuf host; 
    const char *req_result = nullptr;     
    struct {
        bool needed = false;          
        bool usable = false;          
        bool requested = false;       
    } flags;
 
    struct {
        /* all times are absolute unless augmented with _delay */
        time_t initialized = 0; /* creation */
        time_t needed = 0;      /* first lookup/use by a peer */
        time_t next_check = 0;  /* next scheduled check/refresh event */
        time_t retry_delay = 0; /* delay before re-checking _invalid_ digest */
        time_t requested = 0;   /* requested a fresh copy of a digest */
        time_t req_delay = 0;   /* last request response time */
        time_t received = 0;    /* received the current copy of a digest */
        time_t disabled = 0;    /* disabled for good */
    } times;
 
    struct {
        CacheDigestGuessStats guess;
        int used_count = 0;
 
        struct {
            int msgs = 0;
            ByteCounter kbytes;
        } sent, recv;
    } stats;
};
 
extern const Version CacheDigestVer;
 
void peerDigestNeeded(PeerDigest * pd);
void peerDigestNotePeerGone(PeerDigest * pd);
void peerDigestStatsReport(const PeerDigest * pd, StoreEntry * e);
 
#endif /* USE_CACHE_DIGESTS */
 
#endif /* SQUID_SRC_PEERDIGEST_H */