Add MIT license and improve README

Add MIT license file and include it in the Zig package paths.
Rewrite README with badges, installation instructions, usage
example with parameter docs, architecture diagram, and module
descriptions.

Author: bcardarella

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 DockYard, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,38 +1,89 @@
 # flame_on_processor
 
-A Zig library that processes flame graph profiling data into [pprof](https://github.com/google/pprof) protobuf format.
+[![CI](https://github.com/DockYard/flame_on_processor/actions/workflows/ci.yml/badge.svg)](https://github.com/DockYard/flame_on_processor/actions/workflows/ci.yml)
+[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)
 
-Takes semicolon-delimited stack paths with durations, filters out functions below a configurable time threshold, and encodes the result as a pprof `Profile` protobuf.
+A Zig library that transforms flame graph profiling data into the [pprof](https://github.com/google/pprof) protobuf format.
 
-## Usage
+It takes semicolon-delimited stack paths paired with durations, filters out functions that fall below a configurable time threshold, and encodes the result as a pprof `Profile` protobuf — ready for visualization in tools like [pprof](https://github.com/google/pprof) and [speedscope](https://www.speedscope.app).
+
+## Installation
+
+Requires **Zig 0.15.2+**.
+
+```sh
+zig fetch --save git+https://github.com/DockYard/flame_on_processor.git
+```
+
+Then add the dependency in your `build.zig`:
+
+```zig
+const flame_on_processor = b.dependency("flame_on_processor", .{
+    .target = target,
+});
+exe.root_module.addImport("flame_on_processor", flame_on_processor.module("flame_on_processor"));
+```
 
-Add as a Zig package dependency, then import:
+## Usage
 
 ```zig
 const processor = @import("flame_on_processor").processor;
 
 const encoded = try processor.process(
     allocator,
-    &.{ "main;compute", "main;render" },
-    &.{ 3000, 4000 },
+    &.{ "main;compute", "main;render", "main;idle" },
+    &.{ 3000, 4000, 200 },
     0.01, // filter threshold: fraction of total time
 );
 defer allocator.free(encoded);
-// `encoded` is pprof protobuf bytes
+// `encoded` contains pprof protobuf bytes
 ```
 
-## Modules
+### Parameters
 
-- **processor** — top-level API: filter then encode in one call
-- **profile_filter** — removes functions whose inclusive time falls below a threshold fraction, consolidating small subtrees
-- **pprof_encoder** — encodes filtered samples into pprof protobuf wire format
-- **protobuf** — low-level protobuf encoding primitives
+| Parameter   | Type                    | Description                                                                 |
+|-------------|-------------------------|-----------------------------------------------------------------------------|
+| `allocator` | `std.mem.Allocator`     | Allocator for all internal and returned memory                              |
+| `paths`     | `[]const []const u8`    | Semicolon-delimited stack traces (e.g. `"main;compute;render"`)             |
+| `durations` | `[]const u64`           | Duration in microseconds for each path (parallel array)                     |
+| `threshold` | `f64`                   | Fraction of total time below which functions are filtered out (min `0.005`) |
+
+Returns an allocated `[]u8` containing the protobuf-encoded pprof Profile. Caller owns the memory.
+
+## Architecture
+
+```
+         paths + durations
+               │
+               ▼
+      ┌─────────────────┐
+      │    processor     │   top-level API
+      └────────┬────────┘
+               │
+       ┌───────┴───────┐
+       ▼               ▼
+┌──────────────┐ ┌──────────────┐
+│profile_filter│ │pprof_encoder │
+└──────────────┘ └──────┬───────┘
+                        │
+                        ▼
+                 ┌──────────────┐
+                 │   protobuf   │
+                 └──────────────┘
+```
 
-## Building
+- **processor** — top-level API: filter then encode in one call
+- **profile_filter** — removes functions whose inclusive time falls below the threshold, consolidating small subtrees into placeholder entries
+- **pprof_encoder** — encodes filtered samples into pprof protobuf wire format with proper string table deduplication
+- **protobuf** — low-level protobuf encoding primitives (varints, length-delimited fields, packed arrays)
 
-Requires Zig 0.15+.
+## Development
 
 ```sh
-zig build        # build the library
-zig build test   # run tests
+zig build            # build the library
+zig build test       # run all tests
 ```
+
+## License
+
+[MIT](LICENSE) - Copyright (c) 2025 DockYard, Inc.

build.zig.zon

@@ -74,8 +74,6 @@
         "build.zig",
         "build.zig.zon",
         "src",
-        // For example...
-        //"LICENSE",
-        //"README.md",
+        "LICENSE",
     },
 }