gix_archive/
write.rs

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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
use gix_worktree_stream::{Entry, Stream};

use crate::{Error, Format, Options};

/// Write all stream entries in `stream` as provided by `next_entry(stream)` to `out` configured according to `opts` which
/// also includes the streaming format.
///
/// ### Performance
///
/// * The caller should be sure `out` is fast enough. If in doubt, wrap in [`std::io::BufWriter`].
/// * Further, big files aren't suitable for archival into `tar` archives as they require the size of the stream to be known
///   prior to writing the header of each entry.
#[cfg_attr(not(feature = "tar"), allow(unused_mut, unused_variables))]
pub fn write_stream<NextFn>(
    stream: &mut Stream,
    mut next_entry: NextFn,
    out: impl std::io::Write,
    opts: Options,
) -> Result<(), Error>
where
    NextFn: FnMut(&mut Stream) -> Result<Option<Entry<'_>>, gix_worktree_stream::entry::Error>,
{
    if opts.format == Format::InternalTransientNonPersistable {
        return Err(Error::InternalFormatMustNotPersist);
    }
    #[cfg(any(feature = "tar", feature = "tar_gz"))]
    {
        enum State<W: std::io::Write> {
            #[cfg(feature = "tar")]
            Tar((tar::Builder<W>, Vec<u8>)),
            #[cfg(feature = "tar_gz")]
            TarGz((tar::Builder<flate2::write::GzEncoder<W>>, Vec<u8>)),
        }

        impl<W: std::io::Write> State<W> {
            pub fn new(format: Format, mtime: gix_date::SecondsSinceUnixEpoch, out: W) -> Result<Self, Error> {
                Ok(match format {
                    Format::InternalTransientNonPersistable => unreachable!("handled earlier"),
                    Format::Zip { .. } => return Err(Error::ZipWithoutSeek),
                    #[cfg(feature = "tar")]
                    Format::Tar => {
                        #[cfg(feature = "tar")]
                        {
                            State::Tar((
                                {
                                    let mut ar = tar::Builder::new(out);
                                    ar.mode(tar::HeaderMode::Deterministic);
                                    ar
                                },
                                Vec::with_capacity(64 * 1024),
                            ))
                        }
                        #[cfg(not(feature = "tar"))]
                        {
                            Err(Error::SupportNotCompiledIn { wanted: Format::Tar })
                        }
                    }
                    Format::TarGz { compression_level } => {
                        #[cfg(feature = "tar_gz")]
                        {
                            State::TarGz((
                                {
                                    let gz = flate2::GzBuilder::new().mtime(mtime as u32).write(
                                        out,
                                        match compression_level {
                                            None => flate2::Compression::default(),
                                            Some(level) => flate2::Compression::new(u32::from(level)),
                                        },
                                    );
                                    let mut ar = tar::Builder::new(gz);
                                    ar.mode(tar::HeaderMode::Deterministic);
                                    ar
                                },
                                Vec::with_capacity(64 * 1024),
                            ))
                        }
                        #[cfg(not(feature = "tar_gz"))]
                        {
                            Err(Error::SupportNotCompiledIn { wanted: Format::TarGz })
                        }
                    }
                })
            }
        }

        let mut state = State::new(opts.format, opts.modification_time, out)?;
        while let Some(entry) = next_entry(stream)? {
            match &mut state {
                #[cfg(feature = "tar")]
                State::Tar((ar, buf)) => {
                    append_tar_entry(ar, buf, entry, opts.modification_time, &opts)?;
                }
                #[cfg(feature = "tar_gz")]
                State::TarGz((ar, buf)) => {
                    append_tar_entry(ar, buf, entry, opts.modification_time, &opts)?;
                }
            }
        }

        match state {
            #[cfg(feature = "tar")]
            State::Tar((mut ar, _)) => {
                ar.finish()?;
            }
            #[cfg(feature = "tar_gz")]
            State::TarGz((ar, _)) => {
                ar.into_inner()?.finish()?;
            }
        }
    }
    Ok(())
}

/// Like [`write_stream()`], but requires [`std::io::Seek`] for `out`.
///
/// Note that `zip` is able to stream big files, which our `tar` implementation is not able to do, which makes it the
/// only suitable container to support huge files from `git-lfs` without consuming excessive amounts of memory.
#[cfg_attr(not(feature = "zip"), allow(unused_mut, unused_variables))]
pub fn write_stream_seek<NextFn>(
    stream: &mut Stream,
    mut next_entry: NextFn,
    out: impl std::io::Write + std::io::Seek,
    opts: Options,
) -> Result<(), Error>
where
    NextFn: FnMut(&mut Stream) -> Result<Option<Entry<'_>>, gix_worktree_stream::entry::Error>,
{
    let compression_level = match opts.format {
        Format::Zip { compression_level } => compression_level.map(i64::from),
        _other => return write_stream(stream, next_entry, out, opts),
    };

    #[cfg(feature = "zip")]
    {
        let mut ar = zip::write::ZipWriter::new(out);
        let mut buf = Vec::new();
        let zdt = jiff::Timestamp::from_second(opts.modification_time)
            .map_err(|err| Error::InvalidModificationTime(Box::new(err)))?
            .to_zoned(jiff::tz::TimeZone::UTC);
        let mtime = zip::DateTime::from_date_and_time(
            zdt.year()
                .try_into()
                .map_err(|err| Error::InvalidModificationTime(Box::new(err)))?,
            // These are all OK because month, day, hour, minute and second
            // are always positive.
            zdt.month().try_into().expect("non-negative"),
            zdt.day().try_into().expect("non-negative"),
            zdt.hour().try_into().expect("non-negative"),
            zdt.minute().try_into().expect("non-negative"),
            zdt.second().try_into().expect("non-negative"),
        )
        .map_err(|err| Error::InvalidModificationTime(Box::new(err)))?;
        while let Some(entry) = next_entry(stream)? {
            append_zip_entry(
                &mut ar,
                entry,
                &mut buf,
                mtime,
                compression_level,
                opts.tree_prefix.as_ref(),
            )?;
        }
        ar.finish()
            .map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err))?;
    }

    Ok(())
}

#[cfg(feature = "zip")]
fn append_zip_entry<W: std::io::Write + std::io::Seek>(
    ar: &mut zip::write::ZipWriter<W>,
    mut entry: gix_worktree_stream::Entry<'_>,
    buf: &mut Vec<u8>,
    mtime: zip::DateTime,
    compression_level: Option<i64>,
    tree_prefix: Option<&bstr::BString>,
) -> Result<(), Error> {
    let file_opts = zip::write::FileOptions::<'_, ()>::default()
        .compression_method(zip::CompressionMethod::Deflated)
        .compression_level(compression_level)
        .large_file(entry.bytes_remaining().map_or(true, |len| len > u32::MAX as usize))
        .last_modified_time(mtime)
        .unix_permissions(if entry.mode.is_executable() { 0o755 } else { 0o644 });
    let path = add_prefix(entry.relative_path(), tree_prefix).into_owned();
    match entry.mode.kind() {
        gix_object::tree::EntryKind::Blob | gix_object::tree::EntryKind::BlobExecutable => {
            ar.start_file(path.to_string(), file_opts)
                .map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err))?;
            std::io::copy(&mut entry, ar)?;
        }
        gix_object::tree::EntryKind::Tree | gix_object::tree::EntryKind::Commit => {
            ar.add_directory(path.to_string(), file_opts)
                .map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err))?;
        }
        gix_object::tree::EntryKind::Link => {
            use bstr::ByteSlice;
            std::io::copy(&mut entry, buf)?;
            ar.add_symlink(path.to_string(), buf.as_bstr().to_string(), file_opts)
                .map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err))?;
        }
    }
    Ok(())
}

#[cfg(any(feature = "tar", feature = "tar_gz"))]
fn append_tar_entry<W: std::io::Write>(
    ar: &mut tar::Builder<W>,
    buf: &mut Vec<u8>,
    mut entry: gix_worktree_stream::Entry<'_>,
    mtime_seconds_since_epoch: i64,
    opts: &Options,
) -> Result<(), Error> {
    let mut header = tar::Header::new_gnu();
    header.set_mtime(mtime_seconds_since_epoch as u64);
    header.set_entry_type(tar_entry_type(entry.mode));
    header.set_mode(if entry.mode.is_executable() { 0o755 } else { 0o644 });
    buf.clear();
    std::io::copy(&mut entry, buf)?;

    let path = gix_path::from_bstr(add_prefix(entry.relative_path(), opts.tree_prefix.as_ref()));
    header.set_size(buf.len() as u64);

    if entry.mode.is_link() {
        use bstr::ByteSlice;
        let target = gix_path::from_bstr(buf.as_bstr());
        header.set_entry_type(tar::EntryType::Symlink);
        header.set_size(0);
        ar.append_link(&mut header, path, target)?;
    } else {
        ar.append_data(&mut header, path, buf.as_slice())?;
    }
    Ok(())
}

#[cfg(any(feature = "tar", feature = "tar_gz"))]
fn tar_entry_type(mode: gix_object::tree::EntryMode) -> tar::EntryType {
    use gix_object::tree::EntryKind;
    use tar::EntryType;
    match mode.kind() {
        EntryKind::Tree | EntryKind::Commit => EntryType::Directory,
        EntryKind::Blob => EntryType::Regular,
        EntryKind::BlobExecutable => EntryType::Regular,
        EntryKind::Link => EntryType::Link,
    }
}

#[cfg(any(feature = "tar", feature = "tar_gz"))]
fn add_prefix<'a>(relative_path: &'a bstr::BStr, prefix: Option<&bstr::BString>) -> std::borrow::Cow<'a, bstr::BStr> {
    use std::borrow::Cow;
    match prefix {
        None => Cow::Borrowed(relative_path),
        Some(prefix) => {
            use bstr::ByteVec;
            let mut buf = prefix.clone();
            buf.push_str(relative_path);
            Cow::Owned(buf)
        }
    }
}