[skdb] Python bindings proof of concept.

Build:
```
$ (cd sql && skargo build -r --lib)
$ cd pyskdb && pip install .
```

Run:
```
$ python -c "import skdb; skdb.exec('CREATE TABLE foo(a INTEGER, b \
TEXT, c FLOAT); INSERT INTO foo VALUES (1337, \'hello\', \
3.14159267), (42, \'foo\', 2e64)'); print(skdb.exec('SELECT * FROM \
foo'))"
[{'a': 42, 'b': 'foo', 'c': 2e+64}, {'a': 1337, 'b': 'hello', 'c': 3.14159267}]
```

prelude/runtime/runtime64_specific.cpp

@@ -601,33 +601,71 @@ void SKIP_last_tick(uint32_t) {
 void SKIP_switch_to(uint32_t) {
   // Not implemented
 }
+
+void (*SKIP_clear_field_names_ptr)();
 void SKIP_clear_field_names() {
-  // Not implemented
+  if (SKIP_clear_field_names_ptr) {
+    SKIP_clear_field_names_ptr();
+  }
 }
-void SKIP_push_field_name(char*) {
-  // Not implemented
+
+void (*SKIP_push_field_name_ptr)(char*);
+void SKIP_push_field_name(char* val) {
+  if (SKIP_push_field_name_ptr) {
+    SKIP_push_field_name_ptr(val);
+  }
 }
+
+void (*SKIP_clear_object_ptr)();
 void SKIP_clear_object() {
-  // Not implemented
+  if (SKIP_clear_object_ptr) {
+    SKIP_clear_object_ptr();
+  }
 }
+
+void (*SKIP_push_object_field_null_ptr)();
 void SKIP_push_object_field_null() {
-  // Not implemented
+  if (SKIP_push_object_field_null_ptr) {
+    SKIP_push_object_field_null_ptr();
+  }
 }
-void SKIP_push_object_field_int32(int32_t) {
+
+void (*SKIP_push_object_field_int32_ptr)(int32_t);
+void SKIP_push_object_field_int32(int32_t val) {
+  if (SKIP_push_object_field_int32_ptr) {
+    SKIP_push_object_field_int32_ptr(val);
+  }
   // Not implemented
 }
-void SKIP_push_object_field_int64(char*) {
-  // Not implemented
+
+void (*SKIP_push_object_field_int64_ptr)(char*);
+void SKIP_push_object_field_int64(char* val) {
+  if (SKIP_push_object_field_int64_ptr) {
+    SKIP_push_object_field_int64_ptr(val);
+  }
 }
-void SKIP_push_object_field_float(char*) {
-  // Not implemented
+
+void (*SKIP_push_object_field_float_ptr)(char*);
+void SKIP_push_object_field_float(char* val) {
+  if (SKIP_push_object_field_float_ptr) {
+    SKIP_push_object_field_float_ptr(val);
+  }
 }
-void SKIP_push_object_field_string(char*) {
-  // Not implemented
+
+void (*SKIP_push_object_field_string_ptr)(char*);
+void SKIP_push_object_field_string(char* val) {
+  if (SKIP_push_object_field_string_ptr) {
+    SKIP_push_object_field_string_ptr(val);
+  }
 }
+
+void (*SKIP_push_object_ptr)();
 void SKIP_push_object() {
-  // Not implemented
+  if (SKIP_push_object_ptr) {
+    SKIP_push_object_ptr();
+  }
 }
+
 void SKIP_js_delete_fun() {
   // Not implemented
 }

pyskdb/pyproject.toml

@@ -0,0 +1,24 @@
+[build-system]
+requires = [
+    "setuptools>=42",
+    "pybind11>=2.10.0",
+]
+build-backend = "setuptools.build_meta"
+
+
+[tool.cibuildwheel]
+test-command = "python {project}/tests/test.py"
+test-skip = "*universal2:arm64"
+
+
+[tool.ruff]
+target-version = "py37"
+
+[tool.ruff.lint]
+extend-select = [
+  "B",   # flake8-bugbear
+  "I",   # isort
+  "PGH", # pygrep-hooks
+  "RUF", # Ruff-specific
+  "UP",  # pyupgrade
+]

pyskdb/setup.py

@@ -0,0 +1,44 @@
+from pybind11.setup_helpers import Pybind11Extension, build_ext
+from setuptools import setup, Extension
+from setuptools.command.install_lib import install_lib
+from shutil import copyfile
+import os
+
+__version__ = "0.1.0"
+
+libskdb_path = os.path.join("..", "sql", "target", "host", "release", "libskdb.so")
+if not os.path.exists(libskdb_path):
+    raise Exception("libskdb.so not found: build it first (`cargo build -r --lib`)")
+
+copyfile(libskdb_path, "libskdb.so")
+
+ext_modules = [
+    Pybind11Extension(
+        "skdb",
+        sources=["src/skdb.cpp"],
+        libraries=["skdb"],
+        library_dirs=["."],
+        runtime_library_dirs=["."],
+        include_dirs=["../sql/ffi/include"],
+    ),
+]
+
+setup(
+    name="skdb",
+    version=__version__,
+    author="SkipLabs",
+    author_email="contact@skiplabs.io",
+    url="https://github.com/skiplabs/skdb",
+    description="",
+    long_description="",
+    ext_modules=ext_modules,
+    extras_require={"test": "pytest"},
+    # Currently, build_ext only provides an optional "highest supported C++
+    # level" feature, but in the future it may provide more features.
+    cmdclass={"build_ext": build_ext},
+    packages=[''],
+    package_dir={'': '.'},
+    package_data={'': ["libskdb.so"]},
+    zip_safe=False,
+    python_requires=">=3.7",
+)

pyskdb/src/skdb.cpp

@@ -0,0 +1,104 @@
+#include <dlfcn.h>
+#include <pybind11/pybind11.h>
+#include <skdb/skdb.h>
+
+#include <cstdlib>
+#include <vector>
+
+namespace py = pybind11;
+
+namespace pyskdb {
+struct ResultBuilder {
+  std::vector<std::string> field_names;
+  int objectIdx = 0;
+  py::dict object;
+  py::list objects;
+};
+
+ResultBuilder* result = nullptr;
+
+void pySKIP_clear_field_names() {
+  result->field_names.clear();
+}
+
+void pySKIP_push_field_name(char* field_name) {
+  result->field_names.push_back(std::string(field_name));
+}
+
+void pySKIP_clear_object() {
+  result->object = py::dict();
+  result->objectIdx = 0;
+}
+
+void pySKIP_push_object_field_null() {
+  result->object[py::str(result->field_names[result->objectIdx++])] =
+      py::none();
+}
+
+void pySKIP_push_object_field_int32(int32_t val) {
+  result->object[py::str(result->field_names[result->objectIdx++])] = val;
+}
+
+void pySKIP_push_object_field_int64(char* val) {
+  result->object[py::str(result->field_names[result->objectIdx++])] = atol(val);
+}
+
+void pySKIP_push_object_field_float(char* val) {
+  result->object[py::str(result->field_names[result->objectIdx++])] = atof(val);
+}
+
+void pySKIP_push_object_field_string(char* val) {
+  result->object[py::str(result->field_names[result->objectIdx++])] =
+      std::string(val);
+}
+
+void pySKIP_push_object() {
+  result->objects.append(result->object);
+}
+}  // namespace pyskdb
+
+PYBIND11_MODULE(skdb, m) {
+  SKIP_clear_field_names_ptr = &pyskdb::pySKIP_clear_field_names;
+  SKIP_push_field_name_ptr = &pyskdb::pySKIP_push_field_name;
+  SKIP_clear_object_ptr = &pyskdb::pySKIP_clear_object;
+  SKIP_push_object_field_null_ptr = &pyskdb::pySKIP_push_object_field_null;
+  SKIP_push_object_field_int32_ptr = &pyskdb::pySKIP_push_object_field_int32;
+  SKIP_push_object_field_int64_ptr = &pyskdb::pySKIP_push_object_field_int64;
+  SKIP_push_object_field_float_ptr = &pyskdb::pySKIP_push_object_field_float;
+  SKIP_push_object_field_string_ptr = &pyskdb::pySKIP_push_object_field_string;
+  SKIP_push_object_ptr = &pyskdb::pySKIP_push_object;
+
+  m.doc() = R"pbdoc(
+    Skdb -- The reactive database
+    -----------------------------
+
+    .. currentmodule:: skdb
+
+    .. autosummary::
+      :toctree: _generate
+
+      exec
+  )pbdoc";
+
+  m.def(
+      "exec",
+      [](std::string query) {
+        pyskdb::result = new pyskdb::ResultBuilder();
+        void* obstack = SKIP_new_Obstack();
+        char* sk_query = sk_string_create(query.c_str(), query.length());
+        skdb_exec(sk_query);
+        SKIP_destroy_Obstack(obstack);
+
+        auto res = std::move(pyskdb::result->objects);
+        delete pyskdb::result;
+        return res;
+      },
+      py::return_value_policy::copy,
+      R"pbdoc(
+    Execute a query
+
+    TODO
+  )pbdoc");
+
+  m.attr("__version__") = "TODO";
+}

sql/ffi/include/skdb/skdb.h

@@ -0,0 +1,26 @@
+#ifndef __SKDB_H
+#define __SKDB_H
+
+#include <stdint.h>
+
+extern "C" {
+typedef int64_t SkipInt;
+
+extern void (*SKIP_clear_field_names_ptr)();
+extern void (*SKIP_push_field_name_ptr)(char*);
+extern void (*SKIP_clear_object_ptr)();
+extern void (*SKIP_push_object_field_null_ptr)();
+extern void (*SKIP_push_object_field_int32_ptr)(int32_t);
+extern void (*SKIP_push_object_field_int64_ptr)(char*);
+extern void (*SKIP_push_object_field_float_ptr)(char*);
+extern void (*SKIP_push_object_field_string_ptr)(char*);
+extern void (*SKIP_push_object_ptr)();
+
+char* sk_string_create(const char* buffer, uint32_t size);
+void* SKIP_new_Obstack();
+void SKIP_destroy_Obstack(void*);
+
+SkipInt skdb_exec(char* query);
+}
+
+#endif  // __SKDB_H

sql/src/ffi.sk

@@ -0,0 +1,21 @@
+module SKDBFFI;
+
+@cpp_export("skdb_exec")
+fun exec(query: String): Int {
+  SKDB.eval(
+    query,
+    SKDB.Options{
+      alwaysAllowJoins => true,
+      backtrace => true,
+      sync => true,
+      showUsedIndexes => false,
+      format => SKDB.OFK_JS(),
+    },
+    Map[],
+  ) match {
+  | Success _ -> 0
+  | Failure _ -> 1
+  }
+}
+
+module end;