OP-013: Reserve an image id with no accompanying file write

ReserveImageId is invoked over the Imaging route on SAIF.Services.WCF.Services.ImagingService; this page documents the process end to end, from route dispatch to the message the caller receives.

Field	Value
Operation ID	OP-013
Trigger	Caller invokes ReserveImageId over the Imaging route.
Entry operation	ReserveImageId
Owning component	SAIF.Services.WCF.Services.ImagingService.ReserveImageId
Inputs	No request message parts
Outputs	A freshly reserved, monotonic image id.
Failure behavior	Generic SOAP fault, per Faults and error pipeline

Request and response

Direction	Element	Type	Declared in	Notes
Request	—	—	—	No input parts — the request message is empty
Response	long	long	BCL (System)	A freshly reserved, monotonic image id.

Steps

1. unitOfWork.GetRepository<Image>().GetNextImageId() and return, outside any transaction (BR-WCF-024).
2. On failure: an Oracle/NHibernate exception is logged by the installed error handler and surfaced as a generic SOAP fault with exception detail included.

Process flow

The following diagram visualizes this process's control flow.

flowchart TD
    A["unitOfWork.GetRepository<Image>().GetNextImageId() and<br>return, outside any transaction ."]

Transaction and side effects

Aspect	Finding
Unit of work	OracleUnitOfWorkFactory (IMG)
Commit point	Not applicable — no transaction
Records written	Image (id reservation only)
Downstream calls	None
Shared state touched	None
Repeat-call behavior	Each call reserves a new, distinct id

Logging

Surface	Written content
ErrorLogErrorHandler → LogService	Failure-path exception logging only, carrying method signature, calling user and exception detail; see Faults and error pipeline

Faults and error handling

Failure	Fault type the caller receives	Produced by	Source
Oracle/NHibernate exception	Generic SOAP fault	The ErrorLogErrorHandler installed by [LogErrorBehavior]	src/WCF/SAIF.Services.WCF.Host/Services/ImagingService.cs

Authorization

Requirement	Enforced by	Source	Applies to
None in code	IIS authentication on the deployment (see Activation and hosting)	src/WCF/SAIF.Services.WCF.Host/Services/ImagingService.cs	This operation

Related documentation

• Index
• Overview
• Architecture
• Activation and hosting
• Operations
• Faults and error pipeline
• Authentication and authorization
• Dependencies
• Configuration
• Operations and processes
• Business rules
• Data model
• Operational runbook
• Tech debt

Note: Statements marked with * were inferred from code structure, naming conventions, or contextual evidence where direct confirmation was not available in source artifacts. Statements marked with ** could not be confirmed; treat as unknown until verified.

Sources

• src/WCF/SAIF.Services.WCF.Host/Services/ImagingService.cs