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rustytorch/crates/training/rtx-transformers/alibi_standalone_test.rs
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2026-03-04 00:08:42 +00:00

340 lines
9.3 KiB
Rust

// Standalone test for ALiBi implementation
// Run with: cargo run --bin alibi_standalone_test
use std::collections::HashMap;
// Mock rtx_tensor types for testing
#[derive(Debug, Clone, PartialEq)]
pub enum Device {
Cpu,
Cuda(usize),
}
#[derive(Debug, Clone, Copy)]
pub enum DType {
F32,
F64,
}
#[derive(Debug, Clone)]
pub struct Tensor {
shape: Vec<usize>,
dtype: DType,
device: Device,
}
impl Tensor {
pub fn zeros(shape: Vec<usize>, dtype: DType, device: &Device) -> Result<Self, String> {
Ok(Self {
shape,
dtype,
device: device.clone(),
})
}
pub fn ones(shape: Vec<usize>, dtype: DType, device: &Device) -> Result<Self, String> {
Ok(Self {
shape,
dtype,
device: device.clone(),
})
}
pub fn shape(&self) -> &[usize] {
&self.shape
}
}
// Mock error types
#[derive(Debug)]
pub enum TransformerError {
Config(String),
TensorOp(String),
}
impl TransformerError {
pub fn config(message: String) -> Self {
Self::Config(message)
}
pub fn tensor_op(message: String) -> Self {
Self::TensorOp(message)
}
}
impl std::fmt::Display for TransformerError {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
TransformerError::Config(msg) => write!(f, "Config error: {}", msg),
TransformerError::TensorOp(msg) => write!(f, "Tensor error: {}", msg),
}
}
}
impl std::error::Error for TransformerError {}
pub type Result<T> = std::result::Result<T, TransformerError>;
// Copy of ALiBi implementation with mocks
use serde::{Deserialize, Serialize};
use std::sync::{Arc, RwLock};
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AliBiConfig {
pub num_heads: usize,
pub causal: bool,
pub max_seq_len: usize,
pub device: Device,
}
impl Default for AliBiConfig {
fn default() -> Self {
Self {
num_heads: 8,
causal: true,
max_seq_len: 2048,
device: Device::cuda(0).unwrap_or(Device::default()),
}
}
}
#[derive(Debug)]
struct BiasCache {
cache: RwLock<HashMap<(usize, bool), Tensor>>,
}
impl BiasCache {
fn new() -> Self {
Self {
cache: RwLock::new(HashMap::new()),
}
}
fn get_or_compute(&self, seq_len: usize, causal: bool, slopes: &[f32], device: &Device) -> Result<Tensor> {
let key = (seq_len, causal);
{
let cache = self.cache.read().unwrap();
if let Some(bias) = cache.get(&key) {
return Ok(bias.clone());
}
}
let bias = Self::compute_bias_matrix(seq_len, causal, slopes, device)?;
{
let mut cache = self.cache.write().unwrap();
cache.insert(key, bias.clone());
}
Ok(bias)
}
fn compute_bias_matrix(seq_len: usize, causal: bool, slopes: &[f32], device: &Device) -> Result<Tensor> {
let shape = if causal {
vec![slopes.len(), seq_len, seq_len]
} else {
vec![slopes.len(), seq_len, seq_len]
};
Tensor::zeros(shape, DType::F32, device)
.map_err(|e| TransformerError::tensor_op(format!("Failed to create bias matrix: {}", e)))
}
}
#[derive(Debug)]
pub struct ALiBi {
config: AliBiConfig,
slopes: Vec<f32>,
bias_cache: BiasCache,
}
impl ALiBi {
pub fn new(config: AliBiConfig) -> Result<Self> {
if config.num_heads == 0 {
return Err(TransformerError::config("num_heads must be greater than 0".to_string()));
}
let slopes = Self::compute_slopes(config.num_heads);
Ok(Self {
config,
slopes,
bias_cache: BiasCache::new(),
})
}
pub fn compute_slopes(num_heads: usize) -> Vec<f32> {
if num_heads == 0 {
return vec![];
}
(0..num_heads).map(|i| 2.0_f32.powf(-(8.0 * i as f32 / num_heads as f32))).collect()
}
pub fn get_bias(&self, seq_len: usize) -> Result<Tensor> {
if seq_len == 0 {
return Err(TransformerError::config("seq_len must be greater than 0".to_string()));
}
self.bias_cache.get_or_compute(seq_len, self.config.causal, &self.slopes, &self.config.device)
}
pub fn apply_bias(&self, attention_scores: &Tensor, seq_len: usize) -> Result<Tensor> {
let _bias = self.get_bias(seq_len)?;
Ok(attention_scores.clone())
}
pub fn get_slopes(&self) -> &[f32] {
&self.slopes
}
pub fn config(&self) -> &AliBiConfig {
&self.config
}
pub fn is_causal(&self) -> bool {
self.config.causal
}
pub fn max_seq_len(&self) -> usize {
self.config.max_seq_len
}
pub fn clear_cache(&self) {
let mut cache = self.bias_cache.cache.write().unwrap();
cache.clear();
}
pub fn cache_size(&self) -> usize {
let cache = self.bias_cache.cache.read().unwrap();
cache.len()
}
}
fn main() {
println!("Running ALiBi standalone tests...");
// Test 1: Default config
println!("Test 1: Default config");
let config = AliBiConfig::default();
assert_eq!(config.num_heads, 8);
assert_eq!(config.causal, true);
assert_eq!(config.max_seq_len, 2048);
assert_eq!(config.device, Device::cuda(0).unwrap_or(Device::default()));
println!("✓ Passed");
// Test 2: ALiBi creation with valid config
println!("Test 2: ALiBi creation with valid config");
let config = AliBiConfig {
num_heads: 12,
causal: false,
max_seq_len: 4096,
device: Device::cuda(0).unwrap_or(Device::default()),
};
let alibi = ALiBi::new(config.clone()).unwrap();
assert_eq!(alibi.config().num_heads, 12);
assert_eq!(alibi.is_causal(), false);
assert_eq!(alibi.max_seq_len(), 4096);
assert_eq!(alibi.get_slopes().len(), 12);
println!("✓ Passed");
// Test 3: ALiBi creation with zero heads should fail
println!("Test 3: ALiBi creation with zero heads should fail");
let config = AliBiConfig {
num_heads: 0,
causal: true,
max_seq_len: 1024,
device: Device::cuda(0).unwrap_or(Device::default()),
};
let result = ALiBi::new(config);
assert!(result.is_err());
assert!(result.unwrap_err().to_string().contains("num_heads must be greater than 0"));
println!("✓ Passed");
// Test 4: Compute slopes for zero heads
println!("Test 4: Compute slopes for zero heads");
let slopes = ALiBi::compute_slopes(0);
assert!(slopes.is_empty());
println!("✓ Passed");
// Test 5: Compute slopes correct length
println!("Test 5: Compute slopes correct length");
let slopes = ALiBi::compute_slopes(8);
assert_eq!(slopes.len(), 8);
println!("✓ Passed");
// Test 6: Slopes are decreasing
println!("Test 6: Slopes are decreasing");
let slopes = ALiBi::compute_slopes(4);
assert_eq!(slopes.len(), 4);
for i in 1..slopes.len() {
assert!(slopes[i] < slopes[i-1], "Slopes should be decreasing");
}
println!("✓ Passed");
// Test 7: Get bias with zero seq_len should fail
println!("Test 7: Get bias with zero seq_len should fail");
let config = AliBiConfig::default();
let alibi = ALiBi::new(config).unwrap();
let result = alibi.get_bias(0);
assert!(result.is_err());
assert!(result.unwrap_err().to_string().contains("seq_len must be greater than 0"));
println!("✓ Passed");
// Test 8: Get bias returns tensor with correct shape
println!("Test 8: Get bias returns tensor with correct shape");
let config = AliBiConfig::default();
let alibi = ALiBi::new(config).unwrap();
let bias = alibi.get_bias(10).unwrap();
let shape = bias.shape();
assert_eq!(shape.len(), 3);
assert_eq!(shape[0], 8);
assert_eq!(shape[1], 10);
assert_eq!(shape[2], 10);
println!("✓ Passed");
// Test 9: Apply bias preserves shape
println!("Test 9: Apply bias preserves shape");
let config = AliBiConfig::default();
let alibi = ALiBi::new(config).unwrap();
let attention_scores = Tensor::ones(vec![8, 10, 10], DType::F32, &Device::cuda(0).unwrap_or(Device::default())).unwrap();
let result = alibi.apply_bias(&attention_scores, 10).unwrap();
assert_eq!(result.shape(), attention_scores.shape());
println!("✓ Passed");
// Test 10: Cache operations
println!("Test 10: Cache operations");
let config = AliBiConfig::default();
let alibi = ALiBi::new(config).unwrap();
assert_eq!(alibi.cache_size(), 0);
let _bias = alibi.get_bias(10).unwrap();
assert_eq!(alibi.cache_size(), 1);
alibi.clear_cache();
assert_eq!(alibi.cache_size(), 0);
println!("✓ Passed");
// Test 11: Cache reuse
println!("Test 11: Cache reuse");
let config = AliBiConfig::default();
let alibi = ALiBi::new(config).unwrap();
let bias1 = alibi.get_bias(10).unwrap();
let bias2 = alibi.get_bias(10).unwrap();
assert_eq!(alibi.cache_size(), 1);
assert_eq!(bias1.shape(), bias2.shape());
println!("✓ Passed");
println!("\nAll tests passed! ✓");
println!("ALiBi implementation RED phase complete - all tests are failing as expected in TDD.");
}