---
source_files:
  - Common/DTS.Common.ServiceLibrary/ServiceLibrary.cs
  - Common/DTS.Common.ServiceLibrary/IServiceLibrary.cs
generated_at: "2026-04-17T16:36:19.055239+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "50c5239dfd4ea753"
---

# Documentation: DTS.Common.ServiceLibrary

## 1. Purpose

This module provides a Windows Communication Foundation (WCF) service implementation that serves as a basic service library template within the DTS system. It defines a service contract (`IServiceLibrary`) and its implementation (`ServiceLibrary`) with two operations: a simple echo-style data retrieval method and a data contract manipulation method. This appears to be foundational infrastructure code, likely serving as a reference implementation or base service layer that other services in the system may extend or emulate.

---

## 2. Public Interface

### Interface: `IServiceLibrary`
**Location:** `IServiceLibrary.cs`  
**Attribute:** `[ServiceContract]`

| Method | Signature | Description |
|--------|-----------|-------------|
| `GetData` | `string GetData(int value)` | Accepts an integer and returns a formatted string: `"You entered: {value}"`. Marked with `[OperationContract]`. |
| `GetDataUsingDataContract` | `CompositeType GetDataUsingDataContract(CompositeType composite)` | Accepts a `CompositeType` object, conditionally modifies its `StringValue` property, and returns it. Marked with `[OperationContract]`. |

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### Class: `ServiceLibrary`
**Location:** `ServiceLibrary.cs`  
**Implements:** `IServiceLibrary`

| Method | Behavior |
|--------|----------|
| `string GetData(int value)` | Returns `string.Format("You entered: {0}", value)`. |
| `CompositeType GetDataUsingDataContract(CompositeType composite)` | Throws `ArgumentNullException` if `composite` is null. If `composite.BoolValue` is `true`, appends `"Suffix"` to `composite.StringValue`. Returns the modified `composite` object. |

---

### Class: `CompositeType`
**Location:** `IServiceLibrary.cs`  
**Attribute:** `[DataContract]`

| Property | Type | Default Value | Attribute | Description |
|----------|------|---------------|-----------|-------------|
| `BoolValue` | `bool` | `true` | `[DataMember]` | Boolean flag that controls suffix-appending behavior in `GetDataUsingDataContract`. |
| `StringValue` | `string` | `"Hello "` | `[DataMember]` | String value that may be modified by `GetDataUsingDataContract`. |

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## 3. Invariants

1. **Null Argument Handling:** `GetDataUsingDataContract(CompositeType composite)` will always throw `ArgumentNullException` when called with a null reference. The parameter name passed to the exception constructor is `"composite"`.

2. **Conditional Mutation:** In `GetDataUsingDataContract`, the string `"Suffix"` is appended to `StringValue` **if and only if** `BoolValue` evaluates to `true`. No modification occurs when `BoolValue` is `false`.

3. **Default State of CompositeType:** Newly instantiated `CompositeType` objects will always have `BoolValue = true` and `StringValue = "Hello "` unless explicitly changed.

4. **Return Value:** `GetDataUsingDataContract` always returns the same object reference passed in; it never creates a new instance.

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## 4. Dependencies

### This Module Depends On