harn-vm 0.7.58

Async bytecode virtual machine for the Harn programming language
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267

//! Text completion / fill-in-the-middle dispatch. Completion providers
//! fall into three buckets: OpenAI-style `/completions`, Ollama's
//! `/api/generate`, and a chat-based fallback that wraps the prompt in a
//! user message and re-enters the chat path.

use std::collections::BTreeMap;
use std::rc::Rc;

use crate::value::{VmError, VmValue};

use super::auth::apply_auth_headers;
use super::options::LlmCallOptions;
use super::response::{extract_cache_read_tokens, extract_cache_write_tokens};
use super::result::{mock_completion_response, LlmResult};

/// Execute a text completion / fill-in-the-middle call owned by Harn.
pub(crate) async fn vm_call_completion_full(
    opts: &LlmCallOptions,
    prefix: &str,
    suffix: Option<&str>,
) -> Result<LlmResult, VmError> {
    if opts.provider == "mock" {
        return Ok(mock_completion_response(prefix, suffix));
    }

    crate::llm::ensure_real_llm_allowed(&opts.provider)?;

    let resolved = crate::llm_config::provider_config(&opts.provider);
    let completion_endpoint = resolved.and_then(|p| p.completion_endpoint);

    match completion_endpoint.as_deref() {
        Some("/api/generate") => vm_call_completion_ollama(opts, prefix, suffix).await,
        Some(_) => vm_call_completion_openai_style(opts, prefix, suffix).await,
        None => vm_call_completion_fallback(opts, prefix, suffix).await,
    }
}

async fn vm_call_completion_openai_style(
    opts: &LlmCallOptions,
    prefix: &str,
    suffix: Option<&str>,
) -> Result<LlmResult, VmError> {
    let llm_timeout = opts.resolve_timeout();
    let client = crate::llm::shared_blocking_client().clone();

    let pdef = crate::llm_config::provider_config(&opts.provider);
    let base_url = pdef
        .as_ref()
        .map(crate::llm_config::resolve_base_url)
        .unwrap_or_else(|| "https://api.openai.com/v1".to_string());
    let endpoint = pdef
        .as_ref()
        .and_then(|p| p.completion_endpoint.as_deref())
        .unwrap_or("/completions");

    let mut body = serde_json::json!({
        "model": opts.model,
        "prompt": prefix,
        "max_tokens": opts.max_tokens,
    });
    if let Some(suffix) = suffix.filter(|s| !s.is_empty()) {
        body["suffix"] = serde_json::json!(suffix);
    }
    if let Some(temp) = opts.temperature {
        body["temperature"] = serde_json::json!(temp);
    }
    if let Some(top_p) = opts.top_p {
        body["top_p"] = serde_json::json!(top_p);
    }
    if let Some(stop) = &opts.stop {
        body["stop"] = serde_json::json!(stop);
    }
    if let Some(seed) = opts.seed {
        body["seed"] = serde_json::json!(seed);
    }
    if let Some(overrides) = &opts.provider_overrides {
        if let Some(obj) = overrides.as_object() {
            for (k, v) in obj {
                body[k] = v.clone();
            }
        }
    }

    let req = client
        .post(format!("{base_url}{endpoint}"))
        .header("Content-Type", "application/json")
        .timeout(std::time::Duration::from_secs(llm_timeout))
        .json(&body);
    let req = apply_auth_headers(req, &opts.api_key, pdef.as_ref());

    let response = req.send().await.map_err(|e| {
        VmError::Thrown(VmValue::String(Rc::from(format!(
            "{} completion API error: {e}",
            opts.provider
        ))))
    })?;

    let json: serde_json::Value = response.json().await.map_err(|e| {
        VmError::Thrown(VmValue::String(Rc::from(format!(
            "{} completion response parse error: {e}",
            opts.provider
        ))))
    })?;

    if let Some(err) = json["error"]["message"].as_str() {
        return Err(VmError::Thrown(VmValue::String(Rc::from(format!(
            "{} completion API error: {err}",
            opts.provider
        )))));
    }

    Ok(LlmResult {
        text: json["choices"][0]["text"]
            .as_str()
            .unwrap_or("")
            .to_string(),
        tool_calls: Vec::new(),
        input_tokens: json["usage"]["prompt_tokens"].as_i64().unwrap_or(0),
        output_tokens: json["usage"]["completion_tokens"].as_i64().unwrap_or(0),
        cache_read_tokens: extract_cache_read_tokens(&json["usage"]),
        cache_write_tokens: extract_cache_write_tokens(&json["usage"]),
        model: opts.model.clone(),
        provider: opts.provider.clone(),
        thinking: None,
        thinking_summary: None,
        stop_reason: json["choices"][0]["finish_reason"]
            .as_str()
            .map(|s| s.to_string()),
        blocks: vec![serde_json::json!({
            "type": "output_text",
            "text": json["choices"][0]["text"].as_str().unwrap_or(""),
            "visibility": "public",
        })],
    })
}

async fn vm_call_completion_ollama(
    opts: &LlmCallOptions,
    prefix: &str,
    suffix: Option<&str>,
) -> Result<LlmResult, VmError> {
    let llm_timeout = opts.resolve_timeout();
    let client = crate::llm::shared_blocking_client().clone();
    let pdef = crate::llm_config::provider_config(&opts.provider);
    let base_url = pdef
        .as_ref()
        .map(crate::llm_config::resolve_base_url)
        .unwrap_or_else(|| "http://localhost:11434".to_string());
    let endpoint = pdef
        .as_ref()
        .and_then(|p| p.completion_endpoint.as_deref())
        .unwrap_or("/api/generate");

    let mut options = serde_json::Map::new();
    if let Some(temp) = opts.temperature {
        options.insert("temperature".to_string(), serde_json::json!(temp));
    }
    if let Some(top_p) = opts.top_p {
        options.insert("top_p".to_string(), serde_json::json!(top_p));
    }
    if let Some(top_k) = opts.top_k {
        options.insert("top_k".to_string(), serde_json::json!(top_k));
    }
    if let Some(seed) = opts.seed {
        options.insert("seed".to_string(), serde_json::json!(seed));
    }
    if let Some(stop) = &opts.stop {
        options.insert("stop".to_string(), serde_json::json!(stop));
    }
    options.insert(
        "num_predict".to_string(),
        serde_json::json!(opts.max_tokens),
    );

    let mut body = serde_json::json!({
        "model": opts.model,
        "prompt": prefix,
        "stream": false,
        "raw": true,
        "options": options,
    });
    if let Some(suffix) = suffix.filter(|s| !s.is_empty()) {
        body["suffix"] = serde_json::json!(suffix);
    }
    if let Some(system) = &opts.system {
        body["system"] = serde_json::json!(system);
    }
    super::apply_ollama_runtime_settings(&mut body, opts.provider_overrides.as_ref());

    let req = client
        .post(format!("{base_url}{endpoint}"))
        .header("Content-Type", "application/json")
        .timeout(std::time::Duration::from_secs(llm_timeout))
        .json(&body);
    let req = apply_auth_headers(req, &opts.api_key, pdef.as_ref());

    let response = req.send().await.map_err(|e| {
        VmError::Thrown(VmValue::String(Rc::from(format!(
            "{} completion API error: {e}",
            opts.provider
        ))))
    })?;
    let json: serde_json::Value = response.json().await.map_err(|e| {
        VmError::Thrown(VmValue::String(Rc::from(format!(
            "{} completion response parse error: {e}",
            opts.provider
        ))))
    })?;
    if let Some(err) = json["error"].as_str() {
        return Err(VmError::Thrown(VmValue::String(Rc::from(format!(
            "{} completion API error: {err}",
            opts.provider
        )))));
    }

    Ok(LlmResult {
        text: json["response"].as_str().unwrap_or("").to_string(),
        tool_calls: Vec::new(),
        input_tokens: json["prompt_eval_count"].as_i64().unwrap_or(0),
        output_tokens: json["eval_count"].as_i64().unwrap_or(0),
        cache_read_tokens: 0,
        cache_write_tokens: 0,
        model: opts.model.clone(),
        provider: opts.provider.clone(),
        thinking: None,
        thinking_summary: None,
        stop_reason: json["done_reason"].as_str().map(|s| s.to_string()),
        blocks: vec![serde_json::json!({
            "type": "output_text",
            "text": json["response"].as_str().unwrap_or(""),
            "visibility": "public",
        })],
    })
}

async fn vm_call_completion_fallback(
    opts: &LlmCallOptions,
    prefix: &str,
    suffix: Option<&str>,
) -> Result<LlmResult, VmError> {
    let mut fallback_opts = opts.clone();
    let has_suffix = suffix.is_some_and(|s| !s.is_empty());
    let mut bindings = BTreeMap::new();
    bindings.insert("prefix".to_string(), VmValue::String(Rc::from(prefix)));
    bindings.insert("has_suffix".to_string(), VmValue::Bool(has_suffix));
    bindings.insert(
        "suffix".to_string(),
        VmValue::String(Rc::from(suffix.unwrap_or_default())),
    );
    let instruction = crate::stdlib::template::render_stdlib_prompt_asset(
        "llm/prompts/completion_fallback_system.harn.prompt",
        Some(&bindings),
    )?;
    let user_prompt = crate::stdlib::template::render_stdlib_prompt_asset(
        "llm/prompts/completion_fallback_user.harn.prompt",
        Some(&bindings),
    )?;
    fallback_opts.messages = vec![serde_json::json!({
        "role": "user",
        "content": user_prompt,
    })];
    fallback_opts.system = match &opts.system {
        Some(system) => Some(format!("{system}\n\n{instruction}")),
        None => Some(instruction),
    };
    super::vm_call_llm_full(&fallback_opts).await
}