DICOM query result cache with monitoring integration. More...

#include <query_cache.h>

Collaboration diagram for kcenon::pacs::services::cache::query_cache:

Public Types
using	key_type = std::string

using	value_type = cached_query_result

using	size_type = std::size_t

Public Member Functions
	query_cache (const query_cache_config &config=query_cache_config{})
	Construct a query cache with the given configuration.

	query_cache (const query_cache &)=delete
	Non-copyable.

query_cache &	operator= (const query_cache &)=delete

	query_cache (query_cache &&) noexcept=default
	Movable.

query_cache &	operator= (query_cache &&) noexcept=default

	~query_cache ()=default

std::optional< cached_query_result >	get (const key_type &key)
	Retrieve a cached query result.

void	put (const key_type &key, const cached_query_result &result)
	Store a query result in the cache.

void	put (const key_type &key, cached_query_result &&result)
	Store a query result in the cache (move semantics)

bool	invalidate (const key_type &key)
	Remove a specific entry from the cache.

size_type	invalidate_by_prefix (const std::string &prefix)

size_type	invalidate_by_query_level (const std::string &query_level)
	Remove all entries for a specific query level.

template<typename Predicate >
size_type	invalidate_if (Predicate pred)

void	clear ()
	Remove all entries from the cache.

size_type	purge_expired ()
	Remove all expired entries.

size_type	size () const
	Get the current number of cached entries.

bool	empty () const
	Check if the cache is empty.

size_type	max_size () const noexcept
	Get the maximum cache size.

const cache_stats &	stats () const noexcept
	Get cache statistics.

double	hit_rate () const noexcept
	Get the cache hit rate.

void	reset_stats () noexcept
	Reset cache statistics.

Static Public Member Functions
static std::string	build_key (const std::string &query_level, const std::vector< std::pair< std::string, std::string > > &params)
	Build a cache key from query parameters.

static std::string	build_key_with_ae (const std::string &calling_ae, const std::string &query_level, const std::vector< std::pair< std::string, std::string > > &params)
	Build a cache key with AE title prefix.

Private Attributes
query_cache_config	config_

string_lru_cache< cached_query_result >	cache_

Detailed Description

DICOM query result cache with monitoring integration.

This class provides a specialized cache for C-FIND query results with:

LRU eviction policy
Configurable TTL (Time-To-Live)
Integration with PACS monitoring system
Thread-safe concurrent access

Thread Safety: All public methods are thread-safe.

Definition at line 132 of file query_cache.h.

Member Typedef Documentation

◆ key_type

using kcenon::pacs::services::cache::query_cache::key_type = std::string

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 134 of file query_cache.h.

◆ size_type

using kcenon::pacs::services::cache::query_cache::size_type = std::size_t

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 136 of file query_cache.h.

◆ value_type

using kcenon::pacs::services::cache::query_cache::value_type = cached_query_result

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 135 of file query_cache.h.

Constructor & Destructor Documentation

◆ query_cache() [1/3]

kcenon::pacs::services::cache::query_cache::query_cache ( const query_cache_config & config = query_cache_config{} )

explicit

Construct a query cache with the given configuration.

Parameters

config Cache configuration

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 22 of file query_cache.cpp.

    : config_(config)
    , cache_(cache_config{
          config.max_entries,
          config.ttl,
          config.enable_metrics,
          config.cache_name}) {
}

◆ query_cache() [2/3]

kcenon::pacs::services::cache::query_cache::query_cache ( const query_cache & )

delete

Non-copyable.

◆ query_cache() [3/3]

kcenon::pacs::services::cache::query_cache::query_cache ( query_cache && )

defaultnoexcept

Movable.

◆ ~query_cache()

kcenon::pacs::services::cache::query_cache::~query_cache ( )

default

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Member Function Documentation

◆ build_key()

std::string kcenon::pacs::services::cache::query_cache::build_key	(	const std::string &	query_level,
		const std::vector< std::pair< std::string, std::string > > &	params )

staticnodiscard

Build a cache key from query parameters.

Creates a deterministic key from the query level and parameters. The key format is: "level:param1=value1;param2=value2;..." Parameters are sorted by name for consistent key generation.

Parameters

query_level	The query retrieve level (PATIENT, STUDY, SERIES, IMAGE)
params	List of parameter name-value pairs

Returns: Cache key string

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 110 of file query_cache.cpp.

                                                            {
 
    // Sort parameters for consistent key generation
    auto sorted_params = params;
    std::sort(sorted_params.begin(), sorted_params.end(),
              [](const auto& a, const auto& b) { return a.first < b.first; });
 
    std::ostringstream oss;
    oss << query_level << ":";
 
    bool first = true;
    for (const auto& [name, value] : sorted_params) {
        if (!first) {
            oss << ";";
        }
        first = false;
        oss << name << "=" << value;
    }
 
    return oss.str();
}

References name.

Referenced by build_key_with_ae().

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◆ build_key_with_ae()

std::string kcenon::pacs::services::cache::query_cache::build_key_with_ae	(	const std::string &	calling_ae,
		const std::string &	query_level,
		const std::vector< std::pair< std::string, std::string > > &	params )

staticnodiscard

Build a cache key with AE title prefix.

Includes the calling AE title in the key to support per-client caching.

Parameters

calling_ae	The calling AE title
query_level	The query retrieve level
params	List of parameter name-value pairs

Returns: Cache key string

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 134 of file query_cache.cpp.

                                                            {
 
    return calling_ae + "/" + build_key(query_level, params);
}

References build_key().

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◆ clear()

void kcenon::pacs::services::cache::query_cache::clear ( )

Remove all entries from the cache.

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 78 of file query_cache.cpp.

                        {
    cache_.clear();
}

References cache_.

◆ empty()

bool kcenon::pacs::services::cache::query_cache::empty ( ) const

nodiscard

Check if the cache is empty.

Returns: true if no entries are cached

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 90 of file query_cache.cpp.

                              {
    return cache_.empty();
}

References cache_.

◆ get()

std::optional< cached_query_result > kcenon::pacs::services::cache::query_cache::get ( const key_type & key )

nodiscard

Retrieve a cached query result.

If found and not expired, the result is returned and the entry is marked as recently used. Cache metrics are updated.

Parameters

key	The cache key (use build_key to generate)

Returns: The cached result if found, std::nullopt otherwise

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 31 of file query_cache.cpp.

                                                                     {
    return cache_.get(key);
}

References cache_.

◆ hit_rate()

double kcenon::pacs::services::cache::query_cache::hit_rate ( ) const

nodiscardnoexcept

Get the cache hit rate.

Returns: Hit rate as percentage (0.0 to 100.0)

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 102 of file query_cache.cpp.

                                            {
    return cache_.hit_rate();
}

References cache_, and kcenon::pacs::services::cache::cache_stats::hit_rate().

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◆ invalidate()

bool kcenon::pacs::services::cache::query_cache::invalidate ( const key_type & key )

Remove a specific entry from the cache.

Parameters

key	The cache key

Returns: true if the entry was found and removed

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 43 of file query_cache.cpp.

                                                {
    return cache_.invalidate(key);
}

References cache_.

◆ invalidate_by_prefix()

query_cache::size_type kcenon::pacs::services::cache::query_cache::invalidate_by_prefix ( const std::string & prefix )

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 47 of file query_cache.cpp.

                                                                              {
    return cache_.invalidate_if(
        [&prefix](const std::string& key, const cached_query_result&) {
            return key.size() >= prefix.size() &&
                   key.compare(0, prefix.size(), prefix) == 0;
        });
}

References cache_.

◆ invalidate_by_query_level()

query_cache::size_type kcenon::pacs::services::cache::query_cache::invalidate_by_query_level ( const std::string & query_level )

Remove all entries for a specific query level.

Parameters

query_level The query level (PATIENT, STUDY, SERIES, IMAGE)

Returns: Number of entries removed

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 55 of file query_cache.cpp.

                                                                                        {
    // Keys are formatted as "LEVEL:params" or "AE/LEVEL:params"
    // Match both formats
    return cache_.invalidate_if(
        [&query_level](const std::string& key, const cached_query_result&) {
            // Direct match: "LEVEL:..."
            if (key.starts_with(query_level + ":")) {
                return true;
            }
            // AE prefix match: "AE/LEVEL:..."
            auto slash_pos = key.find('/');
            if (slash_pos != std::string::npos) {
                auto level_start = slash_pos + 1;
                auto colon_pos = key.find(':', level_start);
                if (colon_pos != std::string::npos) {
                    auto key_level = key.substr(level_start, colon_pos - level_start);
                    return key_level == query_level;
                }
            }
            return false;
        });
}

References cache_.

◆ invalidate_if()

template<typename Predicate >

size_type kcenon::pacs::services::cache::query_cache::invalidate_if ( Predicate pred )

inline

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 241 of file query_cache.h.

                                            {
        return cache_.invalidate_if(std::move(pred));
    }

References cache_.

◆ max_size()

query_cache::size_type kcenon::pacs::services::cache::query_cache::max_size ( ) const

nodiscardnoexcept

Get the maximum cache size.

Returns: Maximum number of entries

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 94 of file query_cache.cpp.

                                                          {
    return cache_.max_size();
}

References cache_.

◆ operator=() [1/2]

query_cache & kcenon::pacs::services::cache::query_cache::operator= ( const query_cache & )

delete

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

◆ operator=() [2/2]

query_cache & kcenon::pacs::services::cache::query_cache::operator= ( query_cache && )

defaultnoexcept

◆ purge_expired()

query_cache::size_type kcenon::pacs::services::cache::query_cache::purge_expired ( )

Remove all expired entries.

Returns: Number of entries removed

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 82 of file query_cache.cpp.

                                                {
    return cache_.purge_expired();
}

References cache_.

◆ put() [1/2]

void kcenon::pacs::services::cache::query_cache::put	(	const key_type &	key,
		cached_query_result &&	result )

Store a query result in the cache (move semantics)

Parameters

key	The cache key
result	The query result to cache (moved)

Definition at line 39 of file query_cache.cpp.

                                                                       {
    cache_.put(key, std::move(result));
}

References cache_.

◆ put() [2/2]

void kcenon::pacs::services::cache::query_cache::put	(	const key_type &	key,
		const cached_query_result &	result )

Store a query result in the cache.

Parameters

key	The cache key
result	The query result to cache

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 35 of file query_cache.cpp.

                                                                            {
    cache_.put(key, result);
}

References cache_.

◆ reset_stats()

void kcenon::pacs::services::cache::query_cache::reset_stats ( )

noexcept

Reset cache statistics.

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 106 of file query_cache.cpp.

                                       {
    cache_.reset_stats();
}

References cache_.

◆ size()

query_cache::size_type kcenon::pacs::services::cache::query_cache::size ( ) const

nodiscard

Get the current number of cached entries.

Returns: Current cache size

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 86 of file query_cache.cpp.

                                             {
    return cache_.size();
}

References cache_.

◆ stats()

const cache_stats & kcenon::pacs::services::cache::query_cache::stats ( ) const

nodiscardnoexcept

Get cache statistics.

Returns: Reference to cache statistics

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 98 of file query_cache.cpp.

                                                     {
    return cache_.stats();
}

References cache_.

Member Data Documentation

◆ cache_

string_lru_cache<cached_query_result> kcenon::pacs::services::cache::query_cache::cache_

private

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 331 of file query_cache.h.

Referenced by clear(), empty(), get(), hit_rate(), invalidate(), invalidate_by_prefix(), invalidate_by_query_level(), invalidate_if(), max_size(), purge_expired(), put(), put(), reset_stats(), size(), and stats().

◆ config_

query_cache_config kcenon::pacs::services::cache::query_cache::config_

private

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/query_cache.h.

Definition at line 330 of file query_cache.h.

The documentation for this class was generated from the following files:

include/kcenon/pacs/services/cache/query_cache.h
src/services/cache/query_cache.cpp

Public Types

Public Member Functions

Static Public Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ key_type

◆ size_type

◆ value_type

Constructor & Destructor Documentation

◆ query_cache() [1/3]

◆ query_cache() [2/3]

◆ query_cache() [3/3]

◆ ~query_cache()

Member Function Documentation

◆ build_key()

◆ build_key_with_ae()

◆ clear()

◆ empty()

◆ get()

◆ hit_rate()

◆ invalidate()

◆ invalidate_by_prefix()

◆ invalidate_by_query_level()

◆ invalidate_if()

◆ max_size()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ purge_expired()

◆ put() [1/2]

◆ put() [2/2]

◆ reset_stats()

◆ size()

◆ stats()

Member Data Documentation

◆ cache_

◆ config_