From e17048eddfe2df86abd2d498da2a33b9c3dd8a72 Mon Sep 17 00:00:00 2001
From: Jan Tuomi <jan@jantuomi.fi>
Date: Fri, 2 May 2025 23:38:23 +0300
Subject: Add sort_asc param, impl demo chat app

---
 demo/app.py                             | 231 +++++++-------------------------
 demo/requirements.txt                   |   1 +
 demo/static/styles.css                  |  76 +----------
 demo/templates/base.html.j2             |  17 ++-
 demo/templates/frag_aside.html.j2       |  27 ----
 demo/templates/frag_aside_link.html.j2  |   9 --
 demo/templates/frag_error.html.j2       |  16 ---
 demo/templates/frag_form_delete.html.j2 |   7 -
 demo/templates/frag_form_find.html.j2   |   7 -
 demo/templates/frag_form_range.html.j2  |  21 ---
 demo/templates/frag_form_upsert.html.j2 |   5 -
 demo/templates/frag_messages.html.j2    |  12 ++
 demo/templates/frag_results.html.j2     |  18 ---
 demo/templates/page_error.html.j2       |   9 +-
 demo/templates/page_index.html.j2       |  27 ++++
 demo/templates/page_main.html.j2        |  11 --
 log_db/src/common.rs                    |   2 +
 log_db/src/engine.rs                    |  23 +++-
 log_db/tests/integration.rs             |   3 +
 py_bindings/log_db.pyi                  |   6 +-
 py_bindings/src/lib.rs                  |  36 ++++-
 21 files changed, 175 insertions(+), 389 deletions(-)
 delete mode 100644 demo/templates/frag_aside.html.j2
 delete mode 100644 demo/templates/frag_aside_link.html.j2
 delete mode 100644 demo/templates/frag_error.html.j2
 delete mode 100644 demo/templates/frag_form_delete.html.j2
 delete mode 100644 demo/templates/frag_form_find.html.j2
 delete mode 100644 demo/templates/frag_form_range.html.j2
 delete mode 100644 demo/templates/frag_form_upsert.html.j2
 create mode 100644 demo/templates/frag_messages.html.j2
 delete mode 100644 demo/templates/frag_results.html.j2
 create mode 100644 demo/templates/page_index.html.j2
 delete mode 100644 demo/templates/page_main.html.j2

diff --git a/demo/app.py b/demo/app.py
index be79432..bab20f0 100644
--- a/demo/app.py
+++ b/demo/app.py
@@ -1,19 +1,23 @@
 from dotenv import load_dotenv
+from werkzeug.utils import redirect
 load_dotenv()
 
 import os
 import sys
 import traceback
 import tempfile
-from typing import cast
 from flask import Flask, render_template, request
 from flask_compress import Compress # type: ignore
+from flask_apscheduler import APScheduler #type: ignore
+import datetime
+from dataclasses import dataclass
 
-import log_db
+import uuid
 from log_db import DB, Bound, Value
 
 app = Flask(__name__)
 Compress(app)
+scheduler = APScheduler()
 
 BASE_URL = os.environ["BASE_URL"]
 DB_DIR = os.environ["DB_DIR"] if "DB_DIR" in os.environ else tempfile.TemporaryDirectory().name
@@ -22,26 +26,27 @@ print("""\n"""
       f"""BASE_URL:      {BASE_URL}\n"""
       f"""DB_DIR:        {DB_DIR}\n""")
 
-db_fields = ["id", "name"]
-db_types = ["int", "string"]
+db_fields = ["id", "ts", "username", "message"]
+db_types  = ["string", "int", "string", "string"]
+
+@dataclass
+class Message:
+    id: str
+    ts: str
+    username: str
+    msg: str
 
 db = DB \
     .configure() \
     .data_dir(DB_DIR) \
     .fields(db_fields) \
     .primary_key("id") \
-    .secondary_keys(["name"]) \
+    .secondary_keys(["ts"]) \
     .initialize()
 
 def error(e: str, code: int):
     error_text = f"HTTP {code}: {e}"
-    #return render_template("page_error.html.j2", error = error_text)
-
-    htmp_target = request.form.get("htmp") or request.args.get("htmp")
-    if htmp_target:
-        return render_template("frag_error.html.j2", error = error_text, container = htmp_target)
-    else:
-        return render_template("page_error.html.j2", error = error_text)
+    return render_template("page_error.html.j2", error = error_text)
 
 @app.errorhandler(Exception)
 def error_handler(e: Exception):
@@ -52,191 +57,53 @@ def error_handler(e: Exception):
         return error("Internal Server Error", 500)
 
 @app.get("/")
-def index_default():
-    return index("find")
-
-@app.get("/<op>")
-def index(op: str):
-    if op not in ["find", "range", "upsert", "delete"]:
-        return error("Invalid operation", 400)
-
-    rows = db.range_by("id", Bound.unbounded(), Bound.unbounded(), limit=100)
-    rows = [[value_to_str(v) for v in row] for row in rows]
+def index():
+    messages = get_messages()
 
     htmp_target = request.form.get("htmp") or request.args.get("htmp")
     if htmp_target:
-        return render_template(f"frag_form_{op}.html.j2")
+        return render_template("frag_messages.html.j2", messages = messages)
     else:
-        return render_template('page_main.html.j2',
-            selected_form = f"frag_form_{op}.html.j2",
-            field_names = ["id", "name"],
-            rows = rows,
-        )
+        return render_template("page_index.html.j2", messages = messages)
 
-@app.post("/find")
+@app.post("/")
 def query_find():
-    field = request.form.get("field")
-    if not field: raise ValueError("Field is required")
+    username = request.form.get("username")
+    if not username: raise ValueError("username is required")
 
-    values = request.form.get("values")
-    if not values: raise ValueError("Values are required")
+    message = request.form.get("message")
+    if not message: raise ValueError("message is required")
 
-    field_index = db_fields.index(field)
-    if field_index == -1: raise ValueError(f"Field '{field}' not found")
+    id = uuid.uuid4().hex
+    ts = int(datetime.datetime.now().timestamp())
 
-    try:
-        values = [cast_to_value(field, v) for v in values.split("\n")]
-        values = [v for v in values if v is not None]
-    except ValueError as e:
-        return error(str(e), 400)
-
-    tagged_rows = db.batch_find_by(field, values, limit=100)
-    rows = [[value_to_str(v) for v in row] for (_, row) in tagged_rows]
+    db.upsert([Value.string(id), Value.int(ts), Value.string(username), Value.string(message)])
 
     htmp_target = request.form.get("htmp") or request.args.get("htmp")
     if htmp_target:
-        return render_template("frag_results.html.j2",
-            field_names = ["id", "name"],
-            rows = rows,
-        )
+        messages = get_messages()
+        return render_template("frag_messages.html.j2", messages = messages)
     else:
-        return render_template('page_main.html.j2',
-            selected_form = "frag_form_find.html.j2",
-            field_names = ["id", "name"],
-            rows = rows,
-        )
+        return redirect("/")
 
-@app.post("/range")
-def query_range():
-    field = request.form.get("field")
-    if not field: raise ValueError("Field is required")
-
-    from_type = request.form.get("from_type")
-    if not from_type: raise ValueError("From type is required")
-
-    to_type = request.form.get("to_type")
-    if not to_type: raise ValueError("To type is required")
-
-    field_index = db_fields.index(field)
-    if field_index == -1: raise ValueError(f"Field '{field}' not found")
-
-    match from_type:
-        case "unbounded":
-            bound_lower = Bound.unbounded()
-        case "included":
-            from_value = request.form.get("from_value")
-            try:
-                if not from_value: raise ValueError("From value is required")
-                from_value = cast_to_value(field, from_value)
-            except ValueError as e:
-                return error(str(e), 400)
-            bound_lower = Bound.included(cast(Value, from_value))
-        case "excluded":
-            from_value = request.form.get("from_value")
-            try:
-                if not from_value: raise ValueError("From value is required")
-                from_value = cast_to_value(field, from_value)
-            except ValueError as e:
-                return error(str(e), 400)
-            bound_lower = Bound.excluded(cast(Value, from_value))
-        case _:
-            return error("Invalid from type", 400)
-
-    match to_type:
-        case "unbounded":
-            bound_upper = Bound.unbounded()
-        case "included":
-            to_value = request.form.get("to_value")
-            try:
-                if not to_value: raise ValueError("To value is required")
-                to_value = cast_to_value(field, to_value)
-            except ValueError as e:
-                return error(str(e), 400)
-            bound_upper = Bound.included(cast(Value, to_value))
-        case "excluded":
-            to_value = request.form.get("to_value")
-            try:
-                if not to_value: raise ValueError("To value is required")
-                to_value = cast_to_value(field, to_value)
-            except ValueError as e:
-                return error(str(e), 400)
-            bound_upper = Bound.excluded(cast(Value, to_value))
-        case _:
-            return error("Invalid to type", 400)
-
-    tagged_rows = db.range_by(field, bound_lower, bound_upper, limit=100)
-    rows = [[value_to_str(v) for v in row] for row in tagged_rows]
+def get_messages():
+    messages = db.range_by("ts", Bound.unbounded(), Bound.unbounded(), limit=100, sort_asc=False)
 
-    htmp_target = request.form.get("htmp") or request.args.get("htmp")
-    if htmp_target:
-        return render_template("frag_results.html.j2",
-            field_names = ["id", "name"],
-            rows = rows,
-        )
-    else:
-        return render_template('page_main.html.j2',
-            selected_form = "frag_form_range.html.j2",
-            field_names = ["id", "name"],
-            rows = rows,
+    return [
+        Message(
+            id=id.as_string(),
+            ts=datetime.datetime.fromtimestamp(ts.as_int()).isoformat(),
+            username=username.as_string(),
+            msg=msg.as_string()
         )
+        for [id, ts, username, msg] in messages
+    ]
 
-@app.post("/delete")
-def query_delete():
-    field = request.form.get("field")
-    if not field: raise ValueError("Field is required")
-
-    value = request.form.get("value")
-    if not value: raise ValueError("Value is required")
-
-    field_index = db_fields.index(field)
-    if field_index == -1: raise ValueError(f"Field '{field}' not found")
-
-    try:
-        value = cast_to_value(field, value)
-    except ValueError as e:
-        return error(str(e), 400)
-
-    rows = db.delete_by(field, cast(Value, value))
-    rows = [[value_to_str(v) for v in row] for row in rows]
-
-    htmp_target = request.form.get("htmp") or request.args.get("htmp")
-    if htmp_target:
-        return render_template("frag_results.html.j2",
-            field_names = ["id", "name"],
-            rows = rows,
-        )
-    else:
-        return render_template('page_main.html.j2',
-            selected_form = "frag_form_delete.html.j2",
-            field_names = ["id", "name"],
-            rows = rows,
-        )
-
-
-# Utils
-
-def cast_to_value(field: str, str_value: str) -> Value | None:
-    str_value = str_value.strip()
-    if str_value == "": return None
-    if str_value[0] == "\"":
-        if str_value[-1] != "\"": raise ValueError(f"Invalid string: {str_value}")
-        str_value = str_value[1:-1]
-
-    field_index = db_fields.index(field)
-    if field_index == -1: raise ValueError(f"Field '{field}' not found")
-
-    type = db_types[field_index]
-
-    match type:
-        case "int":    return Value.int(int(str_value))
-        case "string": return Value.string(str_value)
-        case _:        raise ValueError(f"Unsupported type: {type}")
+@scheduler.task('interval', id='my_job', minutes=1)
+def run_maintenance():
+    db.do_maintenance_tasks()
 
-def value_to_str(value: Value) -> str:
-    match value.kind():
-        case log_db.VALUE_INT:     return f"{str(value.as_int())} (int)"
-        case log_db.VALUE_STRING:  return f"\"{value.as_string()}\" (string)"
-        case log_db.VALUE_DECIMAL: return f"{value.as_decimal()} (decimal)"
-        case log_db.VALUE_BYTES:   return f"{value.as_bytes()} (bytes)"
-        case log_db.VALUE_NULL:    return "null"
-        case _:                    raise ValueError(f"Unsupported value kind: {value.kind()}")
+if __name__ == '__main__':
+    scheduler.init_app(app)
+    scheduler.start()
+    app.run()
diff --git a/demo/requirements.txt b/demo/requirements.txt
index b6b9bff..9d4ef16 100644
--- a/demo/requirements.txt
+++ b/demo/requirements.txt
@@ -9,3 +9,4 @@ MarkupSafe==3.0.2
 python-dotenv==1.0.1
 Werkzeug==3.1.3
 zstandard==0.23.0
+Flask-APScheduler==1.13.1
diff --git a/demo/static/styles.css b/demo/static/styles.css
index 82bed74..bcf99dc 100644
--- a/demo/static/styles.css
+++ b/demo/static/styles.css
@@ -31,16 +31,13 @@ body {
     line-height: 24px;
 }
 
-#container {
+#messages {
+    max-height: 60vh;
+    overflow-y: scroll;
+    border: 1px solid black;
+    padding: 8px;
     display: flex;
-    flex-flow: row wrap;
-    justify-content: space-between;
-    align-items: flex-start;
-}
-
-a,
-.contrast {
-    color: var(--blue);
+    flex-direction: column-reverse;
 }
 
 h1 {
@@ -77,64 +74,3 @@ input[type="submit"] {
 
     margin-top: 20px;
 }
-
-button.link,
-input[type="submit"].link {
-    background: none;
-    color: var(--blue);
-    padding: 0;
-    margin: 0;
-    text-decoration: underline;
-    font-family: "Inclusive Sans";
-}
-
-button.red,
-input[type="submit"].red {
-    background-color: var(--red);
-}
-
-button.blue,
-input[type="submit"].blue {
-    background-color: var(--blue);
-}
-
-button.yellow,
-input[type="submit"].yellow {
-    background-color: var(--yellow);
-}
-
-input[type="text"],
-input[type*="date"] {
-    font-size: 16px;
-    color: var(--black);
-}
-
-input[type="text"]:disabled,
-input[type*="date"]:disabled {
-    color: var(--gray);
-}
-
-aside {
-    width: 250px;
-}
-
-main {
-    flex: 1;
-    overflow-y: scroll;
-    max-height: 100%;
-}
-
-table {
-    width: 100%;
-}
-
-th,
-td {
-    min-width: 100px;
-    text-align: left;
-    padding: 7px 5px;
-}
-
-tr:nth-of-type(odd) td {
-    background-color: var(--light-gray-2);
-}
diff --git a/demo/templates/base.html.j2 b/demo/templates/base.html.j2
index 47b3f6c..06ab5fc 100644
--- a/demo/templates/base.html.j2
+++ b/demo/templates/base.html.j2
@@ -6,14 +6,25 @@
     <link rel="preload" href="/static/InclusiveSans-Regular.ttf" as="font" type="font/woff2" crossorigin="anonymous">
     <link rel="stylesheet" href="/static/styles.css"></link>
     {% block head_meta %}
-    <title>Database browser</title>
-    <meta name="description" content="Database browser for log_db">
+    <title>Demo chat app</title>
+    <meta name="description" content="Demo chat app">
     {% endblock %}
 </head>
 <body>
-  <h1><a href="/">Database browser</a></h1>
+  <h1><a href="/">Demo chat app</a></h1>
   {% block content %}{% endblock %}
 
+  <form id="refresh" action="/" hidden method="get" htmp replace="messages">
+      <input id="refresh_hidden" type="hidden" name="nonce" value="">
+  </form>
+
   <script src="/static/htmp.js"></script>
+  <script>
+  setInterval(() => {
+    console.log('refreshing');
+    document.getElementById('refresh_hidden').value = Date.now();
+    document.getElementById('refresh').submit();
+  }, 3000);
+  </script>
 </body>
 </html>
diff --git a/demo/templates/frag_aside.html.j2 b/demo/templates/frag_aside.html.j2
deleted file mode 100644
index 6c5658f..0000000
--- a/demo/templates/frag_aside.html.j2
+++ /dev/null
@@ -1,27 +0,0 @@
-{#
-Params
-    selected_form   Form fragment to include
-#}
-
-<aside id="aside">
-    <h3>Read operations</h3>
-    <ul>
-        {% with href="/find", text="Find" %}
-            <li>{% include "frag_aside_link.html.j2" %}</li>
-        {% endwith %}
-        {% with href="/range", text="Range" %}
-            <li>{% include "frag_aside_link.html.j2" %}</li>
-        {% endwith %}
-    </ul>
-    <h3>Write operations</h3>
-    <ul>
-        {% with href="/upsert", text="Upsert" %}
-            <li>{% include "frag_aside_link.html.j2" %}</li>
-        {% endwith %}
-        {% with href="/delete", text="Delete" %}
-            <li>{% include "frag_aside_link.html.j2" %}</li>
-        {% endwith %}
-    </ul>
-
-    {% include selected_form %}
-</aside>
diff --git a/demo/templates/frag_aside_link.html.j2 b/demo/templates/frag_aside_link.html.j2
deleted file mode 100644
index 9cd6041..0000000
--- a/demo/templates/frag_aside_link.html.j2
+++ /dev/null
@@ -1,9 +0,0 @@
-{#
-Params
-    text    Text to render in the link
-    href    URL to link to
-#}
-
-<form method="GET" action="{{ href }}" htmp replace=form_query>
-    <button class="link" type="submit">{{ text }}</button>
-</form>
diff --git a/demo/templates/frag_error.html.j2 b/demo/templates/frag_error.html.j2
deleted file mode 100644
index c5034cd..0000000
--- a/demo/templates/frag_error.html.j2
+++ /dev/null
@@ -1,16 +0,0 @@
-{#
-Params
-    error       Error message to display
-    container   (optional) id for a div to wrap the error message in
-#}
-
-{% if container %}
-<div id="{{ container }}">
-{% endif %}
-
-<h2>Error</h2>
-{{ error }}
-
-{% if container %}
-</div>
-{% endif %}
diff --git a/demo/templates/frag_form_delete.html.j2 b/demo/templates/frag_form_delete.html.j2
deleted file mode 100644
index 22306c1..0000000
--- a/demo/templates/frag_form_delete.html.j2
+++ /dev/null
@@ -1,7 +0,0 @@
-<form id="form_query" action="/delete" method="post" htmp replace=results>
-    <label for="field">Field</label>
-    <input type="text" name="field" id="field" required>
-    <label for="value">Value</label>
-    <input type="text" name="value" id="value" required>
-    <button type="submit">Run query</button>
-</form>
diff --git a/demo/templates/frag_form_find.html.j2 b/demo/templates/frag_form_find.html.j2
deleted file mode 100644
index cadd44b..0000000
--- a/demo/templates/frag_form_find.html.j2
+++ /dev/null
@@ -1,7 +0,0 @@
-<form id="form_query" action="/find" method="post" htmp replace=results>
-    <label for="field">Field</label>
-    <input type="text" name="field" id="field" required>
-    <label for="values">Values (one per line)</label>
-    <textarea name="values" id="values" required></textarea>
-    <button type="submit">Run query</button>
-</form>
diff --git a/demo/templates/frag_form_range.html.j2 b/demo/templates/frag_form_range.html.j2
deleted file mode 100644
index 84b8024..0000000
--- a/demo/templates/frag_form_range.html.j2
+++ /dev/null
@@ -1,21 +0,0 @@
-<form id="form_query" action="/range" method="post" htmp replace=results>
-    <label for="field">Field</label>
-    <input type="text" name="field" id="field" required>
-    <label for="from_type">Lower bound type</label>
-    <select id="from_type" name="from_type" required>
-        <option value="unbounded">Unbounded</option>
-        <option value="included">Inclusive</option>
-        <option value="excluded">Exclusive</option>
-    </select>
-    <label for="values">Lower bound value</label>
-    <input type="text" name="from_value" id="from_value">
-    <label for="to_type">Upper bound type</label>
-    <select id="to_type" name="to_type" required>
-        <option value="unbounded">Unbounded</option>
-        <option value="included">Inclusive</option>
-        <option value="excluded">Exclusive</option>
-    </select>
-    <label for="values">Upper bound value</label>
-    <input type="text" name="to_value" id="to_value">
-    <button type="submit">Run query</button>
-</form>
diff --git a/demo/templates/frag_form_upsert.html.j2 b/demo/templates/frag_form_upsert.html.j2
deleted file mode 100644
index 68820f5..0000000
--- a/demo/templates/frag_form_upsert.html.j2
+++ /dev/null
@@ -1,5 +0,0 @@
-<form id="form_query" action="/upsert" method="post" htmp replace=results>
-    <label for="values">Values (one per line)</label>
-    <textarea name="values" id="values" required></textarea>
-    <button type="submit">Run query</button>
-</form>
diff --git a/demo/templates/frag_messages.html.j2 b/demo/templates/frag_messages.html.j2
new file mode 100644
index 0000000..0473d16
--- /dev/null
+++ b/demo/templates/frag_messages.html.j2
@@ -0,0 +1,12 @@
+{#
+Params
+    messages    List of message objects to display
+#}
+
+<div id="messages">
+    {% for m in messages %}
+    <div class="message">
+        <small>{{ m.ts }}</small> <strong>{{ m.username }}</strong>: {{ m.msg }}
+    </div>
+    {% endfor %}
+</div>
diff --git a/demo/templates/frag_results.html.j2 b/demo/templates/frag_results.html.j2
deleted file mode 100644
index bfb54e9..0000000
--- a/demo/templates/frag_results.html.j2
+++ /dev/null
@@ -1,18 +0,0 @@
-<table id="results">
-<thead>
-    <tr>
-    {% for field_name in field_names %}
-        <th>{{ field_name }}</th>
-    {% endfor %}
-    </tr>
-</thead>
-<tbody>
-    {% for row in rows %}
-    <tr>
-    {% for field in row %}
-        <td>{{ field }}</td>
-    {% endfor %}
-    </tr>
-    {% endfor %}
-</tbody>
-</table>
diff --git a/demo/templates/page_error.html.j2 b/demo/templates/page_error.html.j2
index 3233283..a3f260e 100644
--- a/demo/templates/page_error.html.j2
+++ b/demo/templates/page_error.html.j2
@@ -1,5 +1,12 @@
 {% extends "base.html.j2" %}
 
 {% block content %}
-{% include "frag_error.html.j2" %}
+<div id="container">
+<h2>Error</h2>
+<p>An error occurred while processing your request.</p>
+
+<pre>
+{{ error }}
+</pre>
+</div>
 {% endblock %}
diff --git a/demo/templates/page_index.html.j2 b/demo/templates/page_index.html.j2
new file mode 100644
index 0000000..2da14ab
--- /dev/null
+++ b/demo/templates/page_index.html.j2
@@ -0,0 +1,27 @@
+{% extends "base.html.j2" %}
+
+{% block content %}
+<div id="container">
+    <h2>Messages</h2>
+    {% include "frag_messages.html.j2" %}
+
+    <form id="send_form" action="/" method="post" htmp replace="messages">
+        <input required minlength="1" maxlength="20" type="text" name="username" placeholder="Username...">
+        <input required minlength="1" maxlength="140" type="text" name="message" placeholder="Message...">
+        <button type="submit">Send</button>
+    </form>
+
+    <script>
+    document.getElementById("send_form").addEventListener("submit", function(event) {
+        // add message immediately to #messages
+        const username = this.querySelector('input[name="username"]').value;
+        const message = this.querySelector('input[name="message"]').value;
+        const ts = new Date(Date.now()).toISOString().slice(0, 10);
+        const messages = document.getElementById("messages");
+        const newMessage = document.createElement("div");
+        newMessage.innerHTML = `<small>${ts}</small> <strong>${username}</strong>: ${message}`;
+        messages.prepend(newMessage);
+    });
+    </script>
+</div>
+{% endblock %}
diff --git a/demo/templates/page_main.html.j2 b/demo/templates/page_main.html.j2
deleted file mode 100644
index 907275f..0000000
--- a/demo/templates/page_main.html.j2
+++ /dev/null
@@ -1,11 +0,0 @@
-{% extends "base.html.j2" %}
-
-{% block content %}
-<div id="container">
-    {% include "frag_aside.html.j2" %}
-
-    <main id="main">
-        {% include "frag_results.html.j2" %}
-    </main>
-</div>
-{% endblock %}
diff --git a/log_db/src/common.rs b/log_db/src/common.rs
index ca9f451..0f6a058 100644
--- a/log_db/src/common.rs
+++ b/log_db/src/common.rs
@@ -564,9 +564,11 @@ impl<T> RangeBounds<T> for OwnedBounds<T> {
 pub struct QueryParams {
     pub offset: usize,
     pub limit: usize,
+    pub sort_asc: bool,
 }
 
 pub static DEFAULT_QUERY_PARAMS: QueryParams = QueryParams {
     offset: 0,
     limit: usize::MAX,
+    sort_asc: true,
 };
diff --git a/log_db/src/engine.rs b/log_db/src/engine.rs
index 0701191..6fb9edf 100644
--- a/log_db/src/engine.rs
+++ b/log_db/src/engine.rs
@@ -306,13 +306,19 @@ impl Engine {
             tagged.extend(mapped);
         }
 
+        if !params.sort_asc {
+            tagged.reverse();
+        }
         let bound_low = params.offset;
         let bound_high = (params.offset + params.limit).min(tagged.len());
         let sliced = &tagged[bound_low..bound_high];
-        let tagged_records = self.read_tagged_log_keys(sliced.into_iter())?;
+        let mut tagged_records = self.read_tagged_log_keys(sliced.into_iter())?;
 
         debug!("Read {} records", tagged_records.len());
 
+        if !params.sort_asc {
+            tagged_records.reverse();
+        }
         Ok(tagged_records)
     }
 
@@ -420,15 +426,26 @@ impl Engine {
             self.secondary_memtables[index].range(indexable_bounds)
         };
 
-        let log_key_batches: Vec<(usize, &LogKey)> =
+        let mut log_key_batches: Vec<(usize, &LogKey)> =
             log_keys.into_iter().map(|log_key| (0, log_key)).collect();
 
+        if !params.sort_asc {
+            log_key_batches.reverse();
+        }
+
         let bound_low = params.offset;
         let bound_high = (params.offset + params.limit).min(log_key_batches.len());
         let sliced = &log_key_batches[bound_low..bound_high];
         let tagged_records = self.read_tagged_log_keys(sliced.into_iter());
 
-        Ok(tagged_records?.into_iter().map(|(_, rec)| rec).collect())
+        let mut result_records: Vec<Row> =
+            tagged_records?.into_iter().map(|(_, rec)| rec).collect();
+
+        if !params.sort_asc {
+            result_records.reverse();
+        }
+
+        Ok(result_records)
     }
 
     /// Ensures that the `self.metadata_file` and `self.data_file` handles are still pointing to the correct files.
diff --git a/log_db/tests/integration.rs b/log_db/tests/integration.rs
index e7c6d73..2012faf 100644
--- a/log_db/tests/integration.rs
+++ b/log_db/tests/integration.rs
@@ -909,6 +909,7 @@ fn test_find_by_with_offset_and_limit() {
             &QueryParams {
                 offset: 2,
                 limit: 3,
+                sort_asc: true,
             },
         )
         .unwrap()
@@ -953,6 +954,7 @@ fn test_batch_find_by_with_offset_and_limit() {
             &QueryParams {
                 offset: 1,
                 limit: 2,
+                sort_asc: true,
             },
         )
         .unwrap()
@@ -995,6 +997,7 @@ fn test_range_by_with_offset_and_limit() {
             &QueryParams {
                 offset: 1,
                 limit: 3,
+                sort_asc: true,
             },
         )
         .unwrap()
diff --git a/py_bindings/log_db.pyi b/py_bindings/log_db.pyi
index aeb6421..9a6db62 100644
--- a/py_bindings/log_db.pyi
+++ b/py_bindings/log_db.pyi
@@ -26,11 +26,11 @@ class DB:
     def configure() -> Config: ...
     def upsert(self, record: Record) -> None: ...
     def get(self, key: str) -> Record: ...
-    def find_by(self, key: str, value: "Value", offset: int = ..., limit: int = ...) -> list[Record]: ...
-    def batch_find_by(self, key: str, values: list["Value"], offset: int = ..., limit: int = ...) -> list[tuple[int, Record]]: ...
+    def find_by(self, key: str, value: "Value", offset: int = ..., limit: int = ..., sort_asc: bool = ...) -> list[Record]: ...
+    def batch_find_by(self, key: str, values: list["Value"], offset: int = ..., limit: int = ..., sort_asc: bool = ...) -> list[tuple[int, Record]]: ...
     def delete(self, key: str) -> list[Record]: ...
     def delete_by(self, key: str, value: "Value") -> list[Record]: ...
-    def range_by(self, key: str, start: "Bound", end: "Bound", offset: int = ..., limit: int = ...) -> list[Record]: ...
+    def range_by(self, key: str, start: "Bound", end: "Bound", offset: int = ..., limit: int = ..., sort_asc: bool = ...) -> list[Record]: ...
     def tx_begin(self) -> None: ...
     def tx_commit(self) -> None: ...
     def tx_rollback(self) -> None: ...
diff --git a/py_bindings/src/lib.rs b/py_bindings/src/lib.rs
index a4abfde..4e125ec 100644
--- a/py_bindings/src/lib.rs
+++ b/py_bindings/src/lib.rs
@@ -307,15 +307,23 @@ impl DB {
         Ok(recs.map(|rec| py_from_record(rec)))
     }
 
-    #[pyo3(signature = (field, key, offset = DEFAULT_QUERY_PARAMS.offset, limit = DEFAULT_QUERY_PARAMS.limit))]
+    #[pyo3(signature = (field, key,
+        offset = DEFAULT_QUERY_PARAMS.offset,
+        limit = DEFAULT_QUERY_PARAMS.limit,
+        sort_asc = DEFAULT_QUERY_PARAMS.sort_asc))]
     pub fn find_by(
         &mut self,
         field: PyField,
         key: &Value,
         offset: usize,
         limit: usize,
+        sort_asc: bool,
     ) -> PyResult<Vec<PyRecord>> {
-        let params = QueryParams { offset, limit };
+        let params = QueryParams {
+            offset,
+            limit,
+            sort_asc,
+        };
         let recs = self
             .db
             .find_by_with_params(&field, &key.record_value, &params)
@@ -324,15 +332,23 @@ impl DB {
         Ok(recs.into_iter().map(|rec| py_from_record(rec)).collect())
     }
 
-    #[pyo3(signature = (field, keys, offset = DEFAULT_QUERY_PARAMS.offset, limit = DEFAULT_QUERY_PARAMS.limit))]
+    #[pyo3(signature = (field, keys,
+        offset = DEFAULT_QUERY_PARAMS.offset,
+        limit = DEFAULT_QUERY_PARAMS.limit,
+        sort_asc = DEFAULT_QUERY_PARAMS.sort_asc))]
     pub fn batch_find_by(
         &mut self,
         field: PyField,
         keys: Vec<Value>,
         offset: usize,
         limit: usize,
+        sort_asc: bool,
     ) -> PyResult<Vec<(usize, PyRecord)>> {
-        let params = QueryParams { offset, limit };
+        let params = QueryParams {
+            offset,
+            limit,
+            sort_asc,
+        };
         let keys: Vec<log_db::Value> = keys.into_iter().map(|key| key.record_value).collect();
         let recs = self
             .db
@@ -345,7 +361,10 @@ impl DB {
             .collect())
     }
 
-    #[pyo3(signature = (field, start, end, offset = DEFAULT_QUERY_PARAMS.offset, limit = DEFAULT_QUERY_PARAMS.limit))]
+    #[pyo3(signature = (field, start, end,
+        offset = DEFAULT_QUERY_PARAMS.offset,
+        limit = DEFAULT_QUERY_PARAMS.limit,
+        sort_asc = DEFAULT_QUERY_PARAMS.sort_asc))]
     pub fn range_by(
         &mut self,
         field: PyField,
@@ -353,8 +372,13 @@ impl DB {
         end: &PyRangeBound,
         offset: usize,
         limit: usize,
+        sort_asc: bool,
     ) -> PyResult<Vec<PyRecord>> {
-        let params = QueryParams { offset, limit };
+        let params = QueryParams {
+            offset,
+            limit,
+            sort_asc,
+        };
         let range = OwnedBounds::new(
             match start {
                 PyRangeBound::Unbounded() => StdBound::Unbounded,
-- 
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