1use std::fs::File;
2use std::io::BufWriter;
3use std::path::{Path, PathBuf};
4
5use anyhow::Context;
6use indicatif::{ProgressBar, ProgressStyle};
7use safetensors::Dtype as StDtype;
8use safetensors::SafeTensors;
9
10use zsfm_gguf::{GGMLType, GGUFMetaValue, GGUFWriter};
11
12use crate::config::{MitraConfig, Task};
13use crate::tensor_map::map_tensor_name;
14
15pub struct ConvertOptions {
16 pub output_dtype: GGMLType,
17}
18
19pub fn convert(
20 shard_paths: &[PathBuf],
21 config: &MitraConfig,
22 opts: &ConvertOptions,
23 output_path: &Path,
24) -> anyhow::Result<()> {
25 let mut writer = GGUFWriter::new();
26 write_metadata(&mut writer, config);
27
28 let shard_bytes: Vec<Vec<u8>> = shard_paths
29 .iter()
30 .map(|p| std::fs::read(p).with_context(|| format!("read {}", p.display())))
31 .collect::<anyhow::Result<_>>()?;
32 let shard_views: Vec<SafeTensors> = shard_bytes
33 .iter()
34 .map(|b| SafeTensors::deserialize(b).context("deserialize shard"))
35 .collect::<anyhow::Result<_>>()?;
36
37 let total: usize = shard_views.iter().map(|s| s.len()).sum();
38 let pb = ProgressBar::new(total as u64);
39 pb.set_style(
40 ProgressStyle::with_template(
41 "{spinner:.green} [{elapsed_precise}] [{bar:40.cyan/blue}] {pos}/{len} {msg}",
42 )
43 .unwrap()
44 .progress_chars("=>-"),
45 );
46
47 let mut mapped = 0usize;
48 let mut skipped: Vec<String> = Vec::new();
49 let mut fallback_count = 0usize;
50
51 for shard in &shard_views {
52 for (hf_name, tensor_view) in shard.tensors() {
53 pb.set_message(hf_name.to_string());
54
55 let gguf_name = match map_tensor_name(&hf_name) {
56 Some(n) => n,
57 None => {
58 skipped.push(hf_name.to_string());
59 pb.inc(1);
60 continue;
61 }
62 };
63
64 let src_dtype = ggml_type_from_st(tensor_view.dtype())
65 .with_context(|| format!("tensor {hf_name}: unsupported dtype {:?}", tensor_view.dtype()))?;
66
67 let raw_data = tensor_view.data();
68 let py_shape = tensor_view.shape();
69 let n_elems: usize = py_shape.iter().product();
70 let innermost = py_shape.last().copied().unwrap_or(1);
71
72 let (dst_dtype, gguf_shape, tensor_data) =
73 if opts.output_dtype == GGMLType::Q8_0 && (innermost % 32 != 0 || n_elems % 32 != 0) {
74 fallback_count += 1;
75 let data = cast_data(raw_data, src_dtype, GGMLType::F32)
76 .with_context(|| format!("tensor {hf_name}: cast failed"))?;
77 let gs = py_shape.iter().rev().map(|&d| d as u64).collect();
78 (GGMLType::F32, gs, data)
79 } else {
80 let dst = opts.output_dtype;
81 let data = cast_data(raw_data, src_dtype, dst)
82 .with_context(|| format!("tensor {hf_name}: cast failed"))?;
83 let gs = py_shape.iter().rev().map(|&d| d as u64).collect();
84 (dst, gs, data)
85 };
86
87 writer.add_tensor(gguf_name, gguf_shape, dst_dtype, tensor_data);
88 mapped += 1;
89 pb.inc(1);
90 }
91 }
92
93 pb.finish_with_message("tensors processed");
94
95 if !skipped.is_empty() {
96 eprintln!("\nWarning: {} tensor(s) skipped:", skipped.len());
97 for name in &skipped {
98 eprintln!(" {name}");
99 }
100 }
101 if fallback_count > 0 {
102 eprintln!("\nNote: {fallback_count} tensor(s) fell back to F32.");
103 }
104
105 println!("Writing {mapped} tensors to {} …", output_path.display());
106 let out_file = File::create(output_path).with_context(|| format!("create {}", output_path.display()))?;
107 let mut buf_writer = BufWriter::new(out_file);
108 writer.write_to(&mut buf_writer)?;
109 println!("Done.");
110 Ok(())
111}
112
113fn write_metadata(writer: &mut GGUFWriter, config: &MitraConfig) {
114 writer.add_metadata("general.architecture", GGUFMetaValue::String("mitra".into()));
115 writer.add_metadata(
116 "general.name",
117 GGUFMetaValue::String(
118 match config.task {
119 Task::Classification => "autogluon/mitra-classifier",
120 Task::Regression => "autogluon/mitra-regressor",
121 }
122 .into(),
123 ),
124 );
125 writer.add_metadata(
126 "task",
127 GGUFMetaValue::String(
128 match config.task {
129 Task::Classification => "classification",
130 Task::Regression => "regression",
131 }
132 .into(),
133 ),
134 );
135 writer.add_metadata("mitra.dim", GGUFMetaValue::Uint32(config.dim as u32));
136 writer.add_metadata("mitra.n_layers", GGUFMetaValue::Uint32(config.n_layers as u32));
137 writer.add_metadata("mitra.n_heads", GGUFMetaValue::Uint32(config.n_heads as u32));
138 writer.add_metadata("mitra.dim_output", GGUFMetaValue::Uint32(config.dim_output as u32));
139}
140
141fn ggml_type_from_st(dtype: StDtype) -> anyhow::Result<GGMLType> {
142 match dtype {
143 StDtype::F32 => Ok(GGMLType::F32),
144 StDtype::F16 => Ok(GGMLType::F16),
145 StDtype::BF16 => Ok(GGMLType::BF16),
146 other => anyhow::bail!("unsupported safetensors dtype: {other:?}"),
147 }
148}
149
150fn cast_data(data: &[u8], src: GGMLType, dst: GGMLType) -> anyhow::Result<Vec<u8>> {
151 if src == dst {
152 return Ok(data.to_vec());
153 }
154 if dst == GGMLType::Q8_0 {
155 let f32_values = decode_to_f32(data, src)?;
156 return quantize_q8_0(&f32_values);
157 }
158 match (src, dst) {
159 (GGMLType::F32, GGMLType::F16) => {
160 let vals = parse_f32_le(data)?;
161 let mut out = Vec::with_capacity(vals.len() * 2);
162 for v in vals {
163 out.extend_from_slice(&f32_to_f16_bits(v).to_le_bytes());
164 }
165 Ok(out)
166 }
167 (GGMLType::F32, GGMLType::BF16) => {
168 let vals = parse_f32_le(data)?;
169 let mut out = Vec::with_capacity(vals.len() * 2);
170 for v in vals {
171 out.extend_from_slice(&((v.to_bits() >> 16) as u16).to_le_bytes());
172 }
173 Ok(out)
174 }
175 (GGMLType::F16, GGMLType::BF16) => {
176 let mut out = Vec::with_capacity(data.len());
177 for c in data.chunks_exact(2) {
178 let f32_val = f16_to_f32(u16::from_le_bytes([c[0], c[1]]));
179 out.extend_from_slice(&((f32_val.to_bits() >> 16) as u16).to_le_bytes());
180 }
181 Ok(out)
182 }
183 (GGMLType::BF16, GGMLType::F32) => {
184 let mut out = Vec::with_capacity(data.len() * 2);
185 for c in data.chunks_exact(2) {
186 let bits = (u16::from_le_bytes([c[0], c[1]]) as u32) << 16;
187 out.extend_from_slice(&bits.to_le_bytes());
188 }
189 Ok(out)
190 }
191 (GGMLType::BF16, GGMLType::F16) => {
192 let mut out = Vec::with_capacity(data.len());
193 for c in data.chunks_exact(2) {
194 let bits = (u16::from_le_bytes([c[0], c[1]]) as u32) << 16;
195 out.extend_from_slice(&f32_to_f16_bits(f32::from_bits(bits)).to_le_bytes());
196 }
197 Ok(out)
198 }
199 (GGMLType::F16, GGMLType::F32) => {
200 let mut out = Vec::with_capacity(data.len() * 2);
201 for c in data.chunks_exact(2) {
202 out.extend_from_slice(&f16_to_f32(u16::from_le_bytes([c[0], c[1]])).to_bits().to_le_bytes());
203 }
204 Ok(out)
205 }
206 _ => anyhow::bail!("unsupported cast: {src:?} → {dst:?}"),
207 }
208}
209
210fn decode_to_f32(data: &[u8], src: GGMLType) -> anyhow::Result<Vec<f32>> {
211 match src {
212 GGMLType::F32 => parse_f32_le(data),
213 GGMLType::F16 => data
214 .chunks_exact(2)
215 .map(|c| Ok(f16_to_f32(u16::from_le_bytes([c[0], c[1]]))))
216 .collect(),
217 GGMLType::BF16 => data
218 .chunks_exact(2)
219 .map(|c| Ok(f32::from_bits((u16::from_le_bytes([c[0], c[1]]) as u32) << 16)))
220 .collect(),
221 GGMLType::Q8_0 => anyhow::bail!("Q8_0 as source not supported"),
222 }
223}
224
225fn quantize_q8_0(values: &[f32]) -> anyhow::Result<Vec<u8>> {
226 const BLOCK: usize = 32;
227 if values.len() % BLOCK != 0 {
228 anyhow::bail!("Q8_0 requires count divisible by {BLOCK}");
229 }
230 let n_blocks = values.len() / BLOCK;
231 let mut out = vec![0u8; n_blocks * 34];
232 for b in 0..n_blocks {
233 let blk = &values[b * BLOCK..(b + 1) * BLOCK];
234 let amax = blk.iter().copied().map(f32::abs).fold(0.0f32, f32::max);
235 let d = if amax == 0.0 { 0.0f32 } else { amax / 127.0 };
236 let d_inv = if d == 0.0 { 0.0f32 } else { 1.0 / d };
237 let base = b * 34;
238 out[base..base + 2].copy_from_slice(&f32_to_f16_bits(d).to_le_bytes());
239 for i in 0..BLOCK {
240 out[base + 2 + i] = (blk[i] * d_inv).round().clamp(-127.0, 127.0) as i8 as u8;
241 }
242 }
243 Ok(out)
244}
245
246fn parse_f32_le(data: &[u8]) -> anyhow::Result<Vec<f32>> {
247 if data.len() % 4 != 0 {
248 anyhow::bail!("f32 data length not divisible by 4");
249 }
250 Ok(data.chunks_exact(4).map(|c| f32::from_le_bytes([c[0], c[1], c[2], c[3]])).collect())
251}
252
253fn f32_to_f16_bits(v: f32) -> u16 {
254 let bits = v.to_bits();
255 let sign = ((bits >> 16) & 0x8000) as u16;
256 let exp = ((bits >> 23) & 0xFF) as i32;
257 let mantissa = bits & 0x007F_FFFF;
258 if exp == 0xFF {
259 return sign | 0x7C00 | if mantissa != 0 { 0x0200 } else { 0 };
260 }
261 let new_exp = exp - 127 + 15;
262 if new_exp >= 31 {
263 return sign | 0x7C00;
264 }
265 if new_exp <= 0 {
266 if new_exp < -10 {
267 return sign;
268 }
269 let m = (mantissa | 0x0080_0000) >> (1 - new_exp);
270 return sign | (m >> 13) as u16;
271 }
272 sign | ((new_exp as u16) << 10) | (mantissa >> 13) as u16
273}
274
275fn f16_to_f32(bits: u16) -> f32 {
276 let sign = ((bits & 0x8000) as u32) << 16;
277 let exp = ((bits >> 10) & 0x1F) as i32;
278 let mantissa = (bits & 0x03FF) as u32;
279 let f32_bits = if exp == 0 {
280 if mantissa == 0 {
281 sign
282 } else {
283 let mut m = mantissa;
284 let mut e = 0i32;
285 while m & 0x0400 == 0 {
286 m <<= 1;
287 e += 1;
288 }
289 sign | ((127 - 15 - e + 1) as u32) << 23 | (m & 0x03FF) << 13
290 }
291 } else if exp == 31 {
292 sign | 0x7F80_0000 | (mantissa << 13)
293 } else {
294 sign | ((exp + 127 - 15) as u32) << 23 | (mantissa << 13)
295 };
296 f32::from_bits(f32_bits)
297}