Page MenuHomePhabricator (Chris)
Files F624282

GitPackIdxV2.cpp
No OneTemporary
Actions

Authored By
Unknown
Size
3 KB
Referenced Files
None
Subscribers
None

GitPackIdxV2.cpp
View Options

#include "GitPackIdxV2.h"
#include <QCryptographicHash>
#include <QDebug>
#include <QFile>
QString GitPackIdxV2::toString(uint8_t const *p)
{
char tmp[41];
for (int i = 0; i < 20; i++) {
sprintf(tmp + i * 2, "%02x", p[i]);
}
return QString::fromLatin1(tmp, 40);
}
uint32_t GitPackIdxV2::read_uint32_be(const void *p)
{
uint8_t const *q = (uint8_t const *)p;
return (q[0] << 24) | (q[1] << 16) | (q[2] << 8) | q[3];
}
uint32_t GitPackIdxV2::get_fanout(const GitPackIdxV2::header_t *t, int i)
{
return read_uint32_be(&t->fanout[i]);
}
const uint8_t *GitPackIdxV2::object(int i) const
{
return d.objects[i].id;
}
const uint32_t GitPackIdxV2::offset(int i) const
{
return read_uint32_be(&d.offsets[i]);
}
const uint32_t GitPackIdxV2::checksum(int i) const
{
return read_uint32_be(&d.checksums[i]);
}
void GitPackIdxV2::clear()
{
d = Data();
}
bool GitPackIdxV2::parse(QIODevice *in)
{
try {
auto Read = [&](void *ptr, size_t len){
return in->read((char *)ptr, len) == len;
};
static char const magic[] = "\xff\x74\x4f\x63\x00\x00\x00\x02";
if (!Read(&d.header, sizeof(d.header))) throw QString("failed to read the idx header");
if (memcmp(d.header.magic, magic, 8) != 0) throw QString("invalid idx header");
uint32_t size = get_fanout(&d.header, 255);
if (size > 100000) throw QString("number of objects in the idx file is too big");
size_t size4 = size * sizeof(uint32_t);
d.objects.resize(size);
d.checksums.resize(size);
d.offsets.resize(size);
if (!Read(&d.objects[0], size * 20)) throw QString("failed to read the objects");
if (!Read(&d.checksums[0], size4)) throw QString("failed to read the checksums");
if (!Read(&d.offsets[0], size4)) throw QString("failed to read the offsets");
if (!Read(&d.trailer, sizeof(d.trailer))) throw QString("failed to read the trailer");
QCryptographicHash sha1(QCryptographicHash::Sha1);
sha1.addData((char const *)&d.header, sizeof(d.header));
sha1.addData((char const *)&d.objects[0], size * 20);
sha1.addData((char const *)&d.checksums[0], size4);
sha1.addData((char const *)&d.offsets[0], size4);
sha1.addData((char const *)&d.trailer.packfile_checksum, sizeof(d.trailer) - 20);
QByteArray chksum = sha1.result();
Q_ASSERT(chksum.size() == 20);
if (memcmp(chksum.data(), d.trailer.idxfile_checksum, 20) != 0) {
throw QString("idx checksum is not correct");
}
for (size_t i = 0; i < size; i++) {
GitPackIdxItem item;
item.id = toString(object(i));
item.offset = offset(i);
item.checksum = checksum(i);
d.item_list.push_back(item);
}
for (size_t i = 0; i < size; i++) {
GitPackIdxItem &item = d.item_list[i];
if (i + 1 < size) {
item.packed_size = d.item_list[i + 1].offset - d.item_list[i].offset;
}
}
return true;
} catch (QString const &e) {
qDebug() << e;
}
return false;
}
bool GitPackIdxV2::parse(const QString &idxfile)
{
clear();
QFile file(idxfile);
if (file.open(QFile::ReadOnly)) {
if (parse(&file)) {
return true;
}
}
return false;
}
const GitPackIdxItem *GitPackIdxV2::item(const QString &id) const
{
for (int i = 0; i < (int)d.item_list.size(); i++) {
if (d.item_list[i].id == id) {
return &d.item_list[i];
}
}
return nullptr;
}
const GitPackIdxItem *GitPackIdxV2::item(size_t offset) const
{
for (GitPackIdxItem const &item : d.item_list) {
if (item.offset == offset) return &item;
}
return nullptr;
}

File Metadata

Mime Type
text/x-c
Expires
Sat, Nov 14, 10:11 PM (1 d, 7 h)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
139526
Default Alt Text
GitPackIdxV2.cpp (3 KB)

Event Timeline