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The Registry library manages the collection of documentation sets (docsets), provides search functionality, and handles symbol indexing.

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Registry::Docset

Represents a single documentation set with metadata, symbol index, and search capabilities. Location: src/libs/registry/docset.h

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Docset Types

From src/libs/registry/docset.h:71-75: 
enum class Type {
    Invalid,
    Dash,    // Dash-compatible docsets
    ZDash    // Zeal-specific format
};

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Public Interface

class Docset final
{
public:
    explicit Docset(QString path);
    
    // Metadata
    bool isValid() const;
    QString name() const;
    QString title() const;
    QStringList keywords() const;
    QString version() const;
    int revision() const;
    QString feedUrl() const;
    QString path() const;
    QString documentPath() const;
    
    // Icon and visual
    QIcon icon() const;
    QIcon symbolTypeIcon(const QString &symbolType) const;
    QUrl indexFileUrl() const;
    
    // Symbol information
    QMap<QString, int> symbolCounts() const;
    int symbolCount(const QString &symbolType) const;
    const QMultiMap<QString, QUrl> &symbols(const QString &symbolType) const;
    
    // Search
    QList<SearchResult> search(const QString &query, 
                               const CancellationToken &token) const;
    QList<SearchResult> relatedLinks(const QUrl &url) const;
    QUrl searchResultUrl(const SearchResult &result) const;
    
    // Configuration
    QUrl baseUrl() const;
    void setBaseUrl(const QUrl &baseUrl);
    bool isFuzzySearchEnabled() const;
    void setFuzzySearchEnabled(bool enabled);
    bool isJavaScriptEnabled() const;
};

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Internal Data

From src/libs/registry/docset.h:87-108: 
QString m_name;
QString m_title;
QStringList m_keywords;
QString m_version;
int m_revision = 0;
QString m_feedUrl;
Docset::Type m_type = Type::Invalid;
QString m_path;
QIcon m_icon;

QUrl m_indexFileUrl;
QString m_indexFilePath;

QMultiMap<QString, QString> m_symbolStrings;
QMap<QString, int> m_symbolCounts;
mutable QMap<QString, QMultiMap<QString, QUrl>> m_symbols;
Util::SQLiteDatabase *m_db = nullptr;

bool m_isFuzzySearchEnabled = false;
bool m_isJavaScriptEnabled = false;

QUrl m_baseUrl;

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Metadata Loading

Docsets use Dash-compatible format:
  • Info.plist: Property list with docset metadata
  • meta.json: Additional Zeal-specific metadata
  • icon.*: Docset icon in various formats
From src/libs/registry/docset.cpp:41-51, the Info.plist keys include: 
CFBundleName            // Docset name
DashDocSetFamily        // Docset family
DashDocSetKeyword       // Search keyword
DashIndexFilePath       // Index page path
IsJavaScriptEnabled     // JavaScript support flag

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SQLite Database Schema

Docsets use SQLite databases for symbol storage and search. The database typically contains:
  • searchIndex table: Main symbol index with name, type, and path columns
  • Custom indexes created by Zeal for performance optimization

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Registry::DocsetRegistry

Manages the collection of all installed docsets. Location: src/libs/registry/docsetregistry.h

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Interface

class DocsetRegistry final : public QObject
{
public:
    explicit DocsetRegistry(QObject *parent = nullptr);
    
    // Model for UI
    QAbstractItemModel *model() const;
    
    // Configuration
    QString storagePath() const;
    void setStoragePath(const QString &path);
    bool isFuzzySearchEnabled() const;
    void setFuzzySearchEnabled(bool enabled);
    
    // Collection management
    int count() const;
    bool contains(const QString &name) const;
    QStringList names() const;
    void loadDocset(const QString &path);
    void unloadDocset(const QString &name);
    void unloadAllDocsets();
    
    // Access
    Docset *docset(const QString &name) const;
    Docset *docset(int index) const;
    Docset *docsetForUrl(const QUrl &url);
    QList<Docset *> docsets() const;
    
    // Search
    void search(const QString &query);
    const QList<SearchResult> &queryResults();
    
signals:
    void docsetLoaded(const QString &name);
    void docsetAboutToBeUnloaded(const QString &name);
    void docsetUnloaded(const QString &name);
    void searchCompleted(const QList<SearchResult> &results);
};

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Internal Structure

From src/libs/registry/docsetregistry.h:66-74: 
QAbstractItemModel *m_model = nullptr;
QString m_storagePath;
bool m_isFuzzySearchEnabled = false;
QThread *m_thread = nullptr;
QMap<QString, Docset *> m_docsets;
CancellationToken m_cancellationToken;

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Search Threading

Search operations can be performed asynchronously:
  • Uses a dedicated thread (m_thread) for intensive searches
  • CancellationToken allows canceling long-running searches
  • Results are emitted via searchCompleted signal

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Registry::SearchQuery

Parses and represents search queries with optional docset filtering. Location: src/libs/registry/searchquery.h

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Query Format

SearchQuery supports docset filtering using the : separator: 
android:setTypeFa      → Search "setTypeFa" in Android docset
java,android:onCreate  → Search in Java AND Android docsets
std::string            → Search "std::string" (:: is preserved)
:find                  → Search ":find" literally
From src/libs/registry/searchquery.h:29-37: 
// Examples:
//   "android:setTypeFa" → docsetFilters = ["android"], coreQuery = "setTypeFa"
//   "noprefix"          → docsetFilters = [], coreQuery = "noprefix"
//   ":find"             → docsetFilters = [], coreQuery = ":find"
//   "std::string"       → docsetFilters = [], coreQuery = "std::string"
//   "c++:std::string"   → docsetFilters = ["c++"], coreQuery = "std::string"
//   "java,android:..." → docsetFilters = ["java", "android"], coreQuery = "..."

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Interface

class SearchQuery
{
public:
    explicit SearchQuery() = default;
    explicit SearchQuery(QString query, const QStringList &keywords = QStringList());
    
    static SearchQuery fromString(const QString &str);
    QString toString() const;
    bool isEmpty() const;
    
    QStringList keywords() const;
    void setKeywords(const QStringList &list);
    bool hasKeywords() const;
    bool hasKeywords(const QStringList &keywords) const;
    int keywordPrefixSize() const;
    
    QString query() const;
    void setQuery(const QString &str);
};

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Registry::SearchResult

Represents a single search result with scoring and match positions. Location: src/libs/registry/searchresult.h

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Structure

From src/libs/registry/searchresult.h:17-36: 
struct SearchResult
{
    QString name;           // Symbol name
    QString type;           // Symbol type (class, function, etc.)
    
    QString urlPath;        // Documentation page path
    QString urlFragment;    // URL fragment/anchor
    
    Docset *docset;        // Parent docset
    
    double score;                    // Relevance score
    QVector<int> matchPositions;     // Character positions of matches
    
    // Sorting by score, then alphabetically
    inline bool operator<(const SearchResult &other) const
    {
        if (score == other.score)
            return QString::compare(name, other.name, Qt::CaseInsensitive) < 0;
        return score > other.score;
    }
};

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Scoring Algorithm

Search results are scored based on:
  • Exact matches: Higher score
  • Prefix matches: Medium score
  • Fuzzy matches: Lower score with distance penalty
  • Position of matches: Earlier matches score higher
The Util::Fuzzy utility (from src/libs/util/fuzzy.h) implements fuzzy string matching with configurable algorithms.

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Search Indexing

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Index Creation

From src/libs/registry/docset.cpp:36-37, Zeal creates custom SQLite indexes: 
constexpr char IndexNamePrefix[] = "__zi_name";  // zi - Zeal index
constexpr char IndexNameVersion[] = "0001";      // Current index version
Indexes are created on-demand during first search to optimize query performance.

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SQLite Full-Text Search

Zeal uses SQLite’s FTS (Full-Text Search) capabilities:
  • Custom scoring function registered via sqlite3_create_function
  • View creation for optimized queries
  • Index management for fast symbol lookup

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CancellationToken

Provides a mechanism to cancel long-running search operations. Location: src/libs/registry/cancellationtoken.h Used throughout search operations to check if the user has initiated a new search, allowing early termination of outdated searches.

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Database Utilities

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Util::SQLiteDatabase

Location: src/libs/util/sqlitedatabase.h Wrapper around SQLite C API providing:
  • Connection management
  • Query execution
  • Error handling
  • Resource cleanup

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Symbol Types

Zeal supports various symbol types from Dash docsets:
  • Class/Type: Classes, interfaces, structs
  • Method/Function: Functions and methods
  • Property/Attribute: Properties and attributes
  • Constant: Constants and enums
  • Guide/Sample: Documentation pages and guides
  • Namespace/Module: Namespaces and modules
Each symbol type can have a custom icon defined in the docset.

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See Also

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