mkpkglists improvements

This overlaid MR changes a couple things, namely the format of the meta package archive and only updating archives when needed.

Update When Needed:

We now use the information_schema.tables AUTO_INCREMENT column to keep track of a "serial number" that can be used to tell us whether we need to update or not.

Metadata Format:

    The SQL logic in this file for package metadata now exactly
    reflects RPC's search logic, without searching for specific
    packages.

    Two command line arguments are available:

        --extended | Include License, Keywords and Groups fields

    When one of these arguments are passed, the script will create
    a packages-meta-ext-v1.json.gz, configured via packagesmetaextfile.

    Archive JSON is in the following format: line-separated package objects
    enclosed in a list:

        [
        {...},
        {...},
        {...}
        ]

    This allows users to stream the archive and process packages
    line-by-line, during the local storage process.

    Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/scripts/mkpkglists.py

 #!/usr/bin/env python3
+"""
+Produces package, package base and user archives for the AUR
+database.
+
+Archives:
+
+    packages.gz               | A line-separated list of package names
+    packages-meta-v1.json     | A type=search RPC-formatted JSON dataset
+    packages-meta-ext-v1.json | An --extended or --all archive
+    pkgbase.gz                | A line-separated list of package base names
+    users.gz                  | A line-separated list of user names
+
+This script takes an optional argument: --extended or --all. Based
+on the following, right-hand side fields are added to each item.
+
+    --extended  | License, Keywords, Groups
+    --all       | License, Keywords, Groups, relations and dependencies
+
+"""
 
 import datetime
 import gzip
-import json
 import os
+import sys
 
 from collections import defaultdict
 from decimal import Decimal
 from typing import Tuple
 
+import orjson
+
 import aurweb.config
 import aurweb.db
 
@@ -22,6 +43,7 @@ def state_path(archive: str) -> str:
 
 packagesfile = aurweb.config.get('mkpkglists', 'packagesfile')
 packagesmetafile = aurweb.config.get('mkpkglists', 'packagesmetafile')
+packagesmetaextfile = aurweb.config.get('mkpkglists', 'packagesmetaextfile')
 packages_state = state_path(packagesfile)
 
 pkgbasefile = aurweb.config.get('mkpkglists', 'pkgbasefile')
@@ -63,57 +85,132 @@ TYPE_MAP = {
     "conflicts": "Conflicts",
     "provides": "Provides",
     "replaces": "Replaces",
-    "groups": "Groups",
-    "license": "License",
-    "keyword": "Keywords"
 }
 
 
-def get_extended_fields(package_id: int, pkgbase_id: int):
+def get_extended_dict(query: str):
+    """
+    Produce data in the form in a single bulk SQL query:
+
+    {
+        <integer_package_id>: {
+            "Depends": [...],
+            "Conflicts": [...],
+            "License": [...]
+        }
+    }
+
+    The caller can then use this data to populate a dataset of packages.
+
+    output = produce_base_output_data()
+    data = get_extended_dict(query)
+    for i in range(len(output)):
+        package_id = output[i].get("ID")
+        output[i].update(data.get(package_id))
+    """
+
+    conn = aurweb.db.Connection()
+
+    cursor = conn.execute(query)
+
+    data = defaultdict(lambda: defaultdict(list))
+
+    for result in cursor.fetchall():
+
+        pkgid = result[0]
+        key = TYPE_MAP.get(result[1])
+        output = result[2]
+        if result[3]:
+            output += result[3]
+
+        # In all cases, we have at least an empty License list.
+        if "License" not in data[pkgid]:
+            data[pkgid]["License"] = []
+
+        # In all cases, we have at least an empty Keywords list.
+        if "Keywords" not in data[pkgid]:
+            data[pkgid]["Keywords"] = []
+
+        if "Groups" not in data[pkgid]:
+            data[pkgid]["Groups"] = []
+
+        data[pkgid][key].append(output)
+
+    conn.close()
+    return data
+
+
+def get_limited_extended_fields():
+    # Returns: [ID, Type, Name, Cond]
+    query = """
+    SELECT PackageGroups.PackageID AS ID, 'Groups' AS Type,
+           Groups.Name, '' AS Cond
+    FROM Groups INNER JOIN PackageGroups
+    ON PackageGroups.GroupID = Groups.ID
+    UNION SELECT PackageLicenses.PackageID AS ID, 'License' AS Type,
+          Licenses.Name, '' as Cond
+    FROM Licenses INNER JOIN PackageLicenses
+    ON PackageLicenses.LicenseID = Licenses.ID
+    UNION SELECT Packages.ID AS ID, 'Keywords' AS Type,
+          PackageKeywords.Keyword AS Name, '' as Cond
+    FROM PackageKeywords
+    INNER JOIN Packages ON Packages.PackageBaseID = PackageKeywords.PackageBaseID
+    """
+    return get_extended_dict(query)
+
+
+def get_extended_fields():
+    # Returns: [ID, Type, Name, Cond]
     query = """
-    SELECT DependencyTypes.Name AS Type,
-    PackageDepends.DepName AS Name,
-    PackageDepends.DepCondition AS Cond
+    SELECT PackageDepends.PackageID AS ID, DependencyTypes.Name AS Type,
+           PackageDepends.DepName AS Name, PackageDepends.DepCondition AS Cond
     FROM PackageDepends
     LEFT JOIN DependencyTypes
     ON DependencyTypes.ID = PackageDepends.DepTypeID
-    WHERE PackageDepends.PackageID = ?
-    UNION SELECT RelationTypes.Name AS Type,
-    PackageRelations.RelName AS Name,
-    PackageRelations.RelCondition AS Cond
+    UNION SELECT PackageRelations.PackageID AS ID, RelationTypes.Name AS Type,
+          PackageRelations.RelName AS Name,
+          PackageRelations.RelCondition AS Cond
     FROM PackageRelations
     LEFT JOIN RelationTypes
     ON RelationTypes.ID = PackageRelations.RelTypeID
-    WHERE PackageRelations.PackageID = ?
-    UNION SELECT 'groups' AS Type, Groups.Name, '' AS Cond
-    FROM Groups INNER JOIN PackageGroups
-    ON PackageGroups.PackageID = ?
-    AND PackageGroups.GroupID = Groups.ID
-    UNION SELECT 'license' AS Type, Licenses.Name, '' as Cond
-    FROM Licenses INNER JOIN PackageLicenses
-    ON PackageLicenses.PackageID = ?
-    AND PackageLicenses.LicenseID = Licenses.ID
-    UNION SELECT 'keyword' AS Type, PackageKeywords.Keyword AS Name, '' as Cond
-    FROM PackageKeywords WHERE PackageBaseID = ?
+    UNION SELECT PackageGroups.PackageID AS ID, 'Groups' AS Type,
+          Groups.Name, '' AS Cond
+    FROM Groups
+    INNER JOIN PackageGroups ON PackageGroups.GroupID = Groups.ID
+    UNION SELECT PackageLicenses.PackageID AS ID, 'License' AS Type,
+          Licenses.Name, '' as Cond
+    FROM Licenses
+    INNER JOIN PackageLicenses ON PackageLicenses.LicenseID = Licenses.ID
+    UNION SELECT Packages.ID AS ID, 'Keywords' AS Type,
+          PackageKeywords.Keyword AS Name, '' as Cond
+    FROM PackageKeywords
+    INNER JOIN Packages ON Packages.PackageBaseID = PackageKeywords.PackageBaseID
     """
+    return get_extended_dict(query)
 
-    conn = aurweb.db.Connection()
 
-    args = [package_id] * 4 + [pkgbase_id]
-    cursor = conn.execute(query, args)
+EXTENDED_FIELD_HANDLERS = {
+    "--extended": get_limited_extended_fields,
+    "--all": get_extended_fields
+}
 
-    data = defaultdict(list)
-    data["License"] = []
-    data["Keywords"] = []
-    for result in cursor.fetchall():
-        key = TYPE_MAP.get(result[0])
-        output = result[1]
-        if result[2]:
-            output += result[2]
-        data[key].append(output)
 
-    conn.close()
-    return data
+def is_decimal(column):
+    """ Check if an SQL column is of decimal.Decimal type. """
+    if isinstance(column, Decimal):
+        return float(column)
+    return column
+
+
+def write_archive(archive: str, output: list):
+    with gzip.open(archive, "wb") as f:
+        f.write(b"[\n")
+        for i, item in enumerate(output):
+            f.write(orjson.dumps(item))
+            if i < len(output) - 1:
+                f.write(b",")
+            f.write(b"\n")
+        f.write(b"]")
 
 
 def main():
@@ -146,53 +243,33 @@ def main():
                            "ON PackageBases.MaintainerUID = Users.ID "
                            "WHERE PackageBases.PackagerUID IS NOT NULL")
 
-        # Store JSON-data in `output`, which can be reused for the
-        # more basic packagesfile generation afterward.
-        output = dict()
-        with gzip.open(packagesmetafile, "wt") as f:
-            """ The output "data" json key points to a list of dictionaries,
-            each representing a single result, filled with column names as
-            keys and column values as values.
-
-            Example:
-                {
-                    "data": [
-                        {
-                            "ID": 123,
-                            "Name": "package_name",
-                            "PackageBaseID": 234,
-                            "Version": "0.1.1",
-                            "Description": "Some description...",
-                            "URL": "https://some.url"
-                        },
-                        ...
-                    ]
-                }
-            """
-
-            def is_decimal(column):
-                if isinstance(column, Decimal):
-                    return float(column)
-                return column
-
-            output = []
-            for result in cur.fetchall():
-                extended_fields = get_extended_fields(result[0], result[2])
-
-                item = {
-                    column[0]: is_decimal(result[i])
-                    for i, column in enumerate(cur.description)
-                }
-                item.update(extended_fields)
-                output.append(item)
-
-            json.dump({
-                "warning": ("This is a experimental! It can be removed "
-                            "or modified without warning!"),
-                "data": output
-            }, f)
-
-        with gzip.open(packagesfile, "w") as f:
+        # Produce packages-meta-v1.json.gz
+        output = list()
+        snapshot_uri = aurweb.config.get("options", "snapshot_uri")
+        for result in cur.fetchall():
+            item = {
+                column[0]: is_decimal(result[i])
+                for i, column in enumerate(cur.description)
+            }
+            item["URLPath"] = snapshot_uri % item.get("Name")
+            output.append(item)
+
+        write_archive(packagesmetafile, output)
+
+        # Produce packages-meta-ext-v1.json.gz
+        if len(sys.argv) > 1 and sys.argv[1] in EXTENDED_FIELD_HANDLERS:
+            f = EXTENDED_FIELD_HANDLERS.get(sys.argv[1])
+            data = f()
+
+            default_ = {"Groups": [], "License": [], "Keywords": []}
+            for i in range(len(output)):
+                data_ = data.get(output[i].get("ID"), default_)
+                output[i].update(data_)
+
+            write_archive(packagesmetaextfile, output)
+
+        # Produce packages.gz
+        with gzip.open(packagesfile, "wb") as f:
             f.write(bytes(pkglist_header + "\n", "UTF-8"))
             f.writelines([
                 bytes(x.get("Name") + "\n", "UTF-8")
@@ -206,6 +283,7 @@ def main():
     updated, update_time = should_update(pkgbases_state, "PackageBases")
     if not updated:
         print("Updating PackageBases...")
+        # Produce pkgbase.gz
         with gzip.open(pkgbasefile, "w") as f:
             f.write(bytes(pkgbaselist_header + "\n", "UTF-8"))
             cur = conn.execute("SELECT Name FROM PackageBases " +
@@ -218,6 +296,7 @@ def main():
     updated, update_time = should_update(users_state, "Users")
     if not updated:
         print("Updating Users...")
+        # Produce users.gz
         with gzip.open(userfile, "w") as f:
             f.write(bytes(userlist_header + "\n", "UTF-8"))
             cur = conn.execute("SELECT UserName FROM Users")