oxibase 0.3.4

Autonomous relational database management system with MVCC, time-travel queries, and full ACID compliance
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

// Copyright 2025 Oxibase Contributors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! Python scripting backend for user-defined functions

use super::ScriptingBackend;
use crate::core::{Error, Result, Value};

#[cfg(feature = "python")]
use rustpython_vm::{
    compiler::Mode, convert::ToPyObject, AsObject, Interpreter, PyObjectRef, PyRef, Settings,
    VirtualMachine,
};

/// Python scripting backend
#[cfg(feature = "python")]
pub struct PythonBackend {
    // Interpreter will be created per execution for isolation
}

#[cfg(feature = "python")]
impl PythonBackend {
    /// Indent each line of the code by 4 spaces for function wrapping
    fn indent_code(&self, code: &str) -> String {
        code.lines()
            .map(|line| format!("    {}", line))
            .collect::<Vec<_>>()
            .join("\n")
    }
}

#[cfg(feature = "python")]
impl PythonBackend {
    /// Create a new Python backend
    pub fn new() -> Self {
        Self {}
    }

    /// Convert Oxibase Value to Python object
    #[allow(dead_code)]
    fn convert_oxibase_to_python(&self, value: &Value, vm: &VirtualMachine) -> Result<PyObjectRef> {
        match value {
            Value::Null(_) => Ok(vm.ctx.none()),
            Value::Integer(i) => Ok(i.to_pyobject(vm)),
            Value::Float(f) => Ok(f.to_pyobject(vm)),
            Value::Text(s) => Ok(s.as_ref().to_pyobject(vm)),
            Value::Boolean(b) => Ok(b.to_pyobject(vm)),
            Value::Timestamp(ts) => {
                // Convert to Python datetime - simplified approach
                // For now, convert to ISO string and let Python handle it
                let iso_str = ts.to_rfc3339();
                Ok(iso_str.to_pyobject(vm))
            }
            Value::Json(j) => {
                // For now, just pass as string
                Ok(j.as_ref().to_pyobject(vm))
            }
        }
    }

    /// Convert Python object back to Oxibase Value
    fn convert_python_to_oxibase(
        &self,
        py_obj: &PyObjectRef,
        vm: &VirtualMachine,
    ) -> Result<Value> {
        if py_obj.is(&vm.ctx.none()) {
            return Ok(Value::null_unknown());
        }

        // Try to extract as different types using str() and parsing
        if let Ok(str_repr) = py_obj.str(vm) {
            // Convert PyStr to String
            let s = str_repr.to_string();
            // Try to parse as different types
            if let Ok(i) = s.parse::<i64>() {
                return Ok(Value::Integer(i));
            }
            if let Ok(f) = s.parse::<f64>() {
                return Ok(Value::Float(f));
            }
            if s == "True" {
                return Ok(Value::Boolean(true));
            }
            if s == "False" {
                return Ok(Value::Boolean(false));
            }
            // For strings and complex objects, return as text or JSON
            return Ok(Value::Text(s.into()));
        }

        // Fallback
        Err(Error::internal("Failed to convert Python object"))
    }

    /// Format Python error with basic error message
    fn format_python_error(
        &self,
        py_err: PyRef<rustpython_vm::builtins::PyBaseException>,
        vm: &VirtualMachine,
    ) -> String {
        // Format error consistently with other backends - try to get string representation
        match py_err.as_object().str(vm) {
            Ok(s) => s.to_string(),
            Err(_) => format!("{:?}", py_err),
        }
    }
}

impl Default for PythonBackend {
    fn default() -> Self {
        Self::new()
    }
}

#[cfg(feature = "python")]
impl ScriptingBackend for PythonBackend {
    fn name(&self) -> &'static str {
        "python"
    }

    fn supported_languages(&self) -> &[&'static str] {
        &["python", "py"]
    }

    fn execute(&self, code: &str, args: &[Value], param_names: &[&str]) -> Result<Value> {
        // Create a new interpreter for each execution (isolation)
        let interpreter = Interpreter::with_init(Settings::default(), |_| ());

        interpreter
            .enter(|vm| {
                let scope = vm.new_scope_with_builtins();

                // Create arguments list for compatibility
                let mut args_vec = Vec::new();
                for arg in args {
                    let py_value = self.convert_oxibase_to_python(arg, vm)?;
                    args_vec.push(py_value);
                }
                let args_list = vm.ctx.new_list(args_vec);
                scope.globals.set_item("arguments", args_list.into(), vm).map_err(|e| {
                    Error::internal(format!("Failed to set arguments list: {:?}", e))
                })?;

                // Convert arguments to Python variables using parameter names
                for (i, arg) in args.iter().enumerate() {
                    let param_name = param_names[i];
                    let py_value = self.convert_oxibase_to_python(arg, vm)?;
                    scope
                        .globals
                        .set_item(param_name, py_value, vm)
                        .map_err(|e| Error::internal(format!("Failed to set argument {}: {:?}", param_name, e)))?;
                }

                // Wrap user code in a function to support 'return' statements
                let indented_code = self.indent_code(code);
                let wrapper_code = format!(
                    "def __user_function():\n{}\nresult = __user_function()",
                    indented_code
                );

                // Execute the wrapper
                match vm.run_code_string(scope.clone(), &wrapper_code, "<user_function>".to_string()) {
                    Ok(_) => {
                        // Check for 'result' (set by the wrapper)
                        match scope.locals.get_item("result", vm) {
                            Ok(result) => self.convert_python_to_oxibase(&result, vm),
                            Err(_) => Err(Error::internal(
                                "Python function did not return a value (use 'return' or set 'result')",
                            )),
                        }
                    }
                    Err(py_err) => {
                        // Convert Python exception to detailed error message
                        let error_msg = self.format_python_error(py_err, vm);
                        Err(Error::internal(format!(
                            "Python execution error: {}",
                            error_msg
                        )))
                    }
                }
            })
            .map_err(|e| Error::internal(format!("Interpreter error: {:?}", e)))
    }

    fn validate_code(&self, code: &str) -> Result<()> {
        // Basic syntax validation using rustpython parsing with wrapper
        let interpreter = Interpreter::with_init(Settings::default(), |_| ());
        interpreter
            .enter(|vm| {
                // Wrap code in function for validation
                let indented_code = self.indent_code(code);
                let wrapper_code = format!(
                    "def __user_function():\n{}\nresult = __user_function()",
                    indented_code
                );

                // Try to compile the wrapped code to check for syntax errors
                match vm.compile(&wrapper_code, Mode::Exec, "<validation>".to_string()) {
                    Ok(_) => Ok(()),
                    Err(e) => Err(Error::internal(format!("Python syntax error: {}", e))),
                }
            })
            .map_err(|e| Error::internal(format!("Validation error: {:?}", e)))
    }
}

/// Stub implementation when Python feature is not enabled
#[cfg(not(feature = "python"))]
pub struct PythonBackend;

#[cfg(not(feature = "python"))]
impl PythonBackend {
    pub fn new() -> Self {
        Self
    }
}

#[cfg(not(feature = "python"))]
impl ScriptingBackend for PythonBackend {
    fn name(&self) -> &'static str {
        "python"
    }

    fn supported_languages(&self) -> &[&'static str] {
        &["python", "py"]
    }

    fn execute(&self, _code: &str, _args: &[Value], _param_names: &[&str]) -> Result<Value> {
        Err(Error::internal(
            "Python backend not enabled. Use --features python to enable Python support",
        ))
    }

    fn validate_code(&self, _code: &str) -> Result<()> {
        Err(Error::internal(
            "Python backend not enabled. Use --features python to enable Python support",
        ))
    }
}