Begin to add support for importing narinfo files

This commit adds the tables, as well as code to support extracting data from
narinfo files.

sqitch/deploy/nar_related_tables.sql

@@ -0,0 +1,53 @@
+-- Deploy guix-data-service:nar_related_tables to pg
+
+BEGIN;
+
+CREATE TABLE nars (
+    id integer PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+    store_path varchar NOT NULL,
+    hash_algorithm varchar NOT NULL,
+    hash varchar NOT NULL,
+    size integer NOT NULL,
+    system varchar,
+    deriver varchar
+);
+
+CREATE TABLE nar_urls (
+    nar_id integer NOT NULL REFERENCES nars(id),
+    url varchar PRIMARY KEY,
+    compression varchar NOT NULL,
+    file_size integer NOT NULL
+);
+
+CREATE TABLE nar_references (
+    nar_id integer NOT NULL REFERENCES nars(id),
+    reference varchar NOT NULL
+);
+
+CREATE TABLE narinfo_signature_public_keys (
+    id integer PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+    sexp_json jsonb NOT NULL,
+    UNIQUE (sexp_json)
+);
+
+CREATE TABLE narinfo_signature_data (
+    id integer PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+    version integer NOT NULL,
+    host_name varchar NOT NULL,
+    data_hash varchar NOT NULL,
+    data_hash_algorithm varchar NOT NULL,
+    data_json jsonb NOT NULL,
+    sig_val_json jsonb NOT NULL,
+    narinfo_signature_public_key_id integer NOT NULL REFERENCES narinfo_signature_public_keys(id),
+    narinfo_body varchar NOT NULL,
+    narinfo_signature_line varchar NOT NULL,
+    UNIQUE (narinfo_signature_line)
+);
+
+CREATE TABLE narinfo_signatures (
+    nar_id integer NOT NULL REFERENCES nars(id),
+    narinfo_signature_data_id integer NOT NULL REFERENCES narinfo_signature_data(id),
+    UNIQUE (nar_id, narinfo_signature_data_id)
+);
+
+COMMIT;