lean_ctx/tools/registered/
ctx_smart_read.rs

1use rmcp::model::Tool;
2use rmcp::ErrorData;
3use serde_json::{json, Map, Value};
4
5use crate::server::tool_trait::{McpTool, ToolContext, ToolOutput};
6use crate::tool_defs::tool_def;
7
8pub struct CtxSmartReadTool;
9
10impl McpTool for CtxSmartReadTool {
11    fn name(&self) -> &'static str {
12        "ctx_smart_read"
13    }
14
15    fn tool_def(&self) -> Tool {
16        tool_def(
17            "ctx_smart_read",
18            "Auto-select optimal read mode for a file.",
19            json!({
20                "type": "object",
21                "properties": {
22                    "path": { "type": "string", "description": "Absolute file path to read" }
23                },
24                "required": ["path"]
25            }),
26        )
27    }
28
29    fn handle(
30        &self,
31        _args: &Map<String, Value>,
32        ctx: &ToolContext,
33    ) -> Result<ToolOutput, ErrorData> {
34        let path = ctx
35            .resolved_path("path")
36            .ok_or_else(|| ErrorData::invalid_params("path is required", None))?
37            .to_string();
38
39        if crate::core::binary_detect::is_binary_file(&path) {
40            let msg = crate::core::binary_detect::binary_file_message(&path);
41            return Err(ErrorData::invalid_params(msg, None));
42        }
43        {
44            let cap = crate::core::limits::max_read_bytes() as u64;
45            if let Ok(meta) = std::fs::metadata(&path) {
46                if meta.len() > cap {
47                    let msg = format!(
48                        "File too large ({} bytes, limit {} bytes via LCTX_MAX_READ_BYTES). \
49                         Use mode=\"lines:1-100\" for partial reads or increase the limit.",
50                        meta.len(),
51                        cap
52                    );
53                    return Err(ErrorData::invalid_params(msg, None));
54                }
55            }
56        }
57
58        tokio::task::block_in_place(|| {
59            let cache_lock = ctx
60                .cache
61                .as_ref()
62                .ok_or_else(|| ErrorData::internal_error("cache not available", None))?;
63            let mut cache = cache_lock.blocking_write();
64            let output = crate::tools::ctx_smart_read::handle(&mut cache, &path, ctx.crp_mode);
65            let original = cache.get(&path).map_or(0, |e| e.original_tokens);
66            let tokens = crate::core::tokens::count_tokens(&output);
67            drop(cache);
68
69            let saved = original.saturating_sub(tokens);
70            Ok(ToolOutput {
71                text: output,
72                original_tokens: original,
73                saved_tokens: saved,
74                mode: Some("auto".to_string()),
75                path: Some(path),
76                changed: false,
77            })
78        })
79    }
80}
lean_ctx/tools/registered/ctx_smart_read.rs

lean_ctx/tools/registered/
ctx_smart_read.rs
