488cc861 |
(in-package :fwoar.cl-git)
|
991d0162 |
(defun extract-object-metadata-from-pack (pack obj-number)
|
b7739814 |
(with-pack-streams (s p) pack
(seek-to-object-in-pack pack s p obj-number)
|
500325f0 |
(read-object-metadata-from-pack p)))
|
991d0162 |
|
488cc861 |
(defun turn-read-object-to-string (object)
|
500325f0 |
(data-lens.lenses:over *object-data-lens*
'babel:octets-to-string object))
|
488cc861 |
(defun fanout-table (s)
(coerce (alexandria:assoc-value
(fwoar.bin-parser:extract '((head 4)
(version 4)
(fanout-table #.(* 4 256) batch-4))
s)
'fanout-table)
'vector))
(defun get-object-size (bytes)
|
6df34ee9 |
(loop for c across bytes
for next = (logand c 15) then (logand c #x7f)
for shift = 0 then (if (= shift 0) 4 (+ shift 7))
for size = next then (+ size (ash next shift))
while (> (logand c #x80) 0)
finally (return size)))
|
488cc861 |
(defun get-object-type (bytes)
(let ((first (elt bytes 0)))
(ldb (byte 3 4)
first)))
(defun get-shas-before (fanout-table first-sha-byte s)
(let ((num-before (elt fanout-table first-sha-byte))
(num-total (alexandria:last-elt fanout-table)))
(values (fwoar.bin-parser:extract (list (list 'shas (* 20 num-before) '->sha-string))
s)
(- num-total num-before))))
(defun advance-past-crcs (obj-count s)
(file-position s
(+ (file-position s)
(* 4 obj-count))))
(defun object-offset (object-number s)
(file-position s
(+ (file-position s)
|
48aa14a3 |
(* (1- object-number)
4)))
|
488cc861 |
(fwoar.bin-parser:extract '((offset 4 fwoar.bin-parser:be->int))
s))
(defun collect-data (idx-toc s num)
(let ((sha-idx (getf idx-toc :shas))
(crc-idx (getf idx-toc :packed-crcs))
(4-byte-offsets-idx (getf idx-toc :4-byte-offsets))
(8-byte-offsets-idx (getf idx-toc :8-byte-offsets)))
|
991d0162 |
(declare (ignore 8-byte-offsets-idx))
|
488cc861 |
(values num
(progn
(file-position s (+ sha-idx (* num 20)))
(read-bytes 20 'fwoar.bin-parser:byte-array-to-hex-string s))
(progn
(file-position s (+ crc-idx (* num 4)))
(read-bytes 4 'identity s))
(progn
(file-position s (+ 4-byte-offsets-idx (* num 4)))
(read-bytes 4 'fwoar.bin-parser:be->int s)))))
(defun read-object-metadata-from-pack (s)
(let* ((metadata (fwoar.bin-parser:extract-high s))
|
88e003ec |
(type-raw (get-object-type metadata))
(size (get-object-size metadata))
(type (object-type->sym type-raw)))
(values (cons :type type)
|
488cc861 |
(cons :decompressed-size size))))
|
b7739814 |
(defun get-first-commits-from-pack (pack n)
(let ((toc (idx-toc pack))
|
488cc861 |
(result ()))
|
b7739814 |
(with-pack-streams (idx pack-s) pack
(dotimes (i n (reverse result))
(multiple-value-bind (_ sha __ offset) (collect-data toc idx i)
(declare (ignore _ __))
(file-position pack-s offset)
(push `((:sha . ,sha)
,@(multiple-value-list
(read-object-metadata-from-pack pack-s))
(:offset . ,offset))
result))))))
|