File size: 2,213 Bytes
1070337 | 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 | -- nixbase32: Encode binary blob to Nix base32 string
--
-- Nix uses a custom base32 alphabet: 0123456789abcdfghijklmnpqrsvwxyz
-- (excludes e, o, t, u)
--
-- The encoding is little-endian
-- Output length: ceil(input_bytes * 8 / 5)
-- 20 bytes (SHA1) -> 32 characters
-- 32 bytes (SHA256) -> 52 characters
--
-- Usage:
-- SELECT nixbase32(file_hash) FROM narinfos;
-- SELECT nixbase32(unhex('e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855'));
CREATE OR REPLACE MACRO nixbase32(input) AS (
SELECT string_agg(
'0123456789abcdfghijklmnpqrsvwxyz'[
((
(COALESCE(byte_arr[bit_pos // 8 + 1], 0) >> (bit_pos % 8)) |
(CASE WHEN (bit_pos % 8) > 3
THEN COALESCE(byte_arr[bit_pos // 8 + 2], 0) << (8 - (bit_pos % 8))
ELSE 0 END)
) & 31) + 1
],
'' ORDER BY n
)
FROM (
SELECT
n,
(out_len - 1 - n) * 5 as bit_pos,
byte_arr
FROM (
SELECT
((octet_length(input)::bigint * 8 + 4) // 5)::bigint as out_len,
list_transform(
generate_series(0::bigint, octet_length(input)::bigint - 1),
i -> (instr('0123456789abcdef', lower(hex(input))[i*2+1]) - 1) * 16 +
(instr('0123456789abcdef', lower(hex(input))[i*2+2]) - 1)
) as byte_arr
) params,
generate_series(0::bigint, out_len - 1) AS t(n)
)
);
-- narURL: Construct NAR URL path from file hash and compression type
--
-- Reconstructs the URL field from a narinfo, which is derived from:
-- nar/<nixbase32(file_hash)>.nar[.<compression_ext>]
--
-- Compression mapping:
-- '' or 'none' -> .nar
-- 'bzip2' -> .nar.bz2
-- 'xz' -> .nar.xz
-- 'zstd' -> .nar.zstd
--
-- Usage:
-- SELECT narURL(file_hash, compression) FROM narinfos;
CREATE OR REPLACE MACRO narURL(file_hash, compression) AS (
'nar/' || nixbase32(file_hash) || '.nar' ||
CASE
WHEN compression = '' OR compression = 'none' THEN ''
WHEN compression = 'bzip2' THEN '.bz2'
ELSE '.' || compression
END
);
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