LoadDateLogHandle

Overview

LoadDateLogHandle is the primary function for populating date collections with data. It supports three modes of operation: loading from file (for DateLog and Holidays), generating date ranges (for DateRange), and automatic merging with conflict resolution. The function handles multi-threaded parsing, validation, and automatic date range generation to extend collections beyond file data.

Purpose

This is a comprehensive loader that serves multiple purposes:

• Parse encrypted date log files with multi-threaded processing
• Load holiday calendars from files
• Generate date ranges programmatically
• Merge date ranges with conflict resolution
• Extend date logs to future dates
• Validate and convert temporary ranges to permanent logs

Key Features

• Multi-threaded file parsing for performance
• Automatic date range generation between two dates
• Conflict resolution strategies (favor source or destination)
• Progress reporting via callback
• Validation and verification of parsed data
• Automatic conversion from range to log after merging
• Market-aware date calculations with holiday skipping

Function Signature

             HRESULT _Must_inspect_result_ _Success_(SUCCEEDED(return)) LoadDateLogHandle(
                 _In_opt_  PFILE_INFO                                                              pFileInfo,
                 _In_opt_  _When_(pFileInfo == NULL, _Notnull_) DATE_ITEM_HANDLE                   hStartDate,
                 _In_opt_  _When_(pFileInfo == NULL, _Notnull_) DATE_ITEM_HANDLE                   hEndDate,
                 _In_	 DATE_LOG_HANDLE                                                           hDateLogHandle,
                 _In_opt_ PDATE_COLLECTION_PROGRESS                                                pProgData,
                 _In_ DWORD                                                                        dwFlags
             );
            

Calling Convention

Standard C calling convention with SAL annotations for parameter validation and return value inspection.

Parameters

Return Values

Success

Handle successfully populated with date data.

Validation Errors

Invalid parameter combination or NULL handle.

The provided hDateLogHandle is invalid or corrupted.

The holidays handle within the datelog is invalid.

End date is not covered by holidays (is a holiday itself).

Range Generation Errors

Date range gap exceeds available capacity or DATE_LOG_MAX limit.

Start and end dates are same or have zero market days between them.

File Processing Errors

Date records in file are malformed or unreadable.

Error reading file data or insufficient data in file.

Resource Errors

Insufficient memory for parsing or range generation.

Behavior by Handle Type

DateLog Handle

DateRange Handle

Holidays Handle

Usage Examples

                    // Create date log and holidays
                    HOLIDAYS_HANDLE hHolidays = NULL;
                    InitializeDateLogHandle(NULL, 0, NULL, &hHolidays, HandleIsForHolidays);

                    PFILE_INFO pHolidaysFile = /* load holidays file */;
                    LoadDateLogHandle(pHolidaysFile, NULL, NULL, hHolidays, NULL, 0);

                    // Create and load date log from file
                    DATE_LOG_HANDLE hDateLog = NULL;
                    InitializeDateLogHandle(NULL, 0, hHolidays, &hDateLog, HandleIsForDatelog);

                    PFILE_INFO pDateFile = /* load date log file */;
                    HRESULT hr = LoadDateLogHandle(
                        pDateFile,           // File with date data
                        NULL,
                        NULL,
                        hDateLog,
                        NULL,
                        0
                    );

                    if (SUCCEEDED(hr)) {
                        DWORD count = GetDateCollectionLength(hDateLog);
                        printf("Loaded %d dates from file\n", count);
                    }
             

                    // Create range handle
                    DATE_RANGE_HANDLE hRange = NULL;
                    InitializeDateLogHandle(NULL, 10000, hHolidays, &hRange, HandleIsForRange);

                    // Generate dates from start to end
                    DATE_ITEM_HANDLE hStart = /* ... */;
                    DATE_ITEM_HANDLE hEnd = /* ... */;

                    HRESULT hr = LoadDateLogHandle(
                        NULL,               // No file
                        hStart,             // Start date for generation
                        hEnd,               // End date for generation
                        hRange,             // Target range
                        NULL,
                        0
                    );

                    if (SUCCEEDED(hr)) {
                        hr = MergeDateLogHandle(hMainLog, hRange,
                        DATE_RANGE_MERGE_FAVOR_SOURCE);
                    }

                    FreeDateCollectionHandle(hRange);
            

Performance Considerations

File Parsing

• Uses worker thread pool for parallel chunk processing
• Chunk size: 62,400 bytes per thread
• Thread count: min(4, processor_count)
• Suitable for files up to 2GB in size

Date Range Generation

• Linear time complexity: O(n) where n = number of business days
• Skips weekends and holidays automatically
• Typical performance: ~1,000,000 dates/second
• Memory: ~680 bytes per date item

Important Notes

Related Functions

• InitializeDateLogHandle() - Create handle before loading
• MergeDateLogHandle() - Merge loaded ranges
• DuplicateDateLogHandle() - Create concurrent access handle