JES is a lightweight, resource-constrained JSON library engineered specifically for embedded applications operating under strict hardware limitations, such as limited stack size and no dynamic memory allocation. The library maintains full compliance with the ECMA-404 JSON standard, ensuring interoperability with standard JSON data while operating efficiently within the constraints of resource-limited environment.
JES provides a simple and efficient API to:
- Parse a JSON string into a tree of JSON elements.
- Modify the elements in place.
- Serialize the tree back into a JSON string.
- ✅ No dynamic memory allocation – All objects are stored in a single working buffer, ensuring predictable memory usage.
- ✅ Non-recursive parser – Designed to handle deep JSON structures without relying on recursion, making it suitable for environments with limited stack size.
- ✅ Concurrent document handling – Supports parsing multiple JSON documents simultaneously by using a separate parser context and working buffer for each document.
- ✅ High performance – Operates directly on the input buffer without copying data, ensuring minimal processing overhead.
- ✅ No external dependencies – Fully self-contained, making it easy to integrate into embedded projects.
- ✅ Fast Key search – Can be configured at compile time to utilise a hash table key lookup for faster key searching in large JSON data.
- ✅ Flexible output formatting – The output can be generated as a compact string or formatted with indentation for readability.
While JES is designed to be a robust and efficient JSON parser for embedded and resource-constrained environments, it has certain limitations that should be taken into account when evaluating it for your project.
JES is optimized for small JSON documents (typically a few kilobytes) used in configuration or control systems. It is not intended for parsing or manipulating large, complex JSON structures. Below are key limitations to be aware of:
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No Dynamic Memory Allocation - JES avoids dynamic memory allocation and works with user-provided memory buffers. This has implications:
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The user must pre-allocate enough memory based on an estimate of the maximum JSON size.
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When creating or modifying JSON elements, the user is responsible for storing and maintaining any new string values.
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Not Thread-Safe - JES does not provide internal synchronization and is not safe for use across multiple threads unless externally protected.
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Limited JSON Feature Support - JES focuses on core JSON parsing and does not currently support advanced features such as JSON Pointer, JSONPath, or other modern JSON querying standards.