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
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
use libc::{c_int, c_uint, c_void, size_t};
use std::marker;
use std::ptr;
use std::slice;

use crate::util::Binding;
use crate::{panic, raw, Buf, Error, Oid, Repository, Revwalk};

/// Stages that are reported by the `PackBuilder` progress callback.
pub enum PackBuilderStage {
    /// Adding objects to the pack
    AddingObjects,
    /// Deltafication of the pack
    Deltafication,
}

pub type ProgressCb<'a> = dyn FnMut(PackBuilderStage, u32, u32) -> bool + 'a;
pub type ForEachCb<'a> = dyn FnMut(&[u8]) -> bool + 'a;

/// A builder for creating a packfile
pub struct PackBuilder<'repo> {
    raw: *mut raw::git_packbuilder,
    progress: Option<Box<Box<ProgressCb<'repo>>>>,
    _marker: marker::PhantomData<&'repo Repository>,
}

impl<'repo> PackBuilder<'repo> {
    /// Insert a single object. For an optimal pack it's mandatory to insert
    /// objects in recency order, commits followed by trees and blobs.
    pub fn insert_object(&mut self, id: Oid, name: Option<&str>) -> Result<(), Error> {
        let name = crate::opt_cstr(name)?;
        unsafe {
            try_call!(raw::git_packbuilder_insert(self.raw, id.raw(), name));
        }
        Ok(())
    }

    /// Insert a root tree object. This will add the tree as well as all
    /// referenced trees and blobs.
    pub fn insert_tree(&mut self, id: Oid) -> Result<(), Error> {
        unsafe {
            try_call!(raw::git_packbuilder_insert_tree(self.raw, id.raw()));
        }
        Ok(())
    }

    /// Insert a commit object. This will add a commit as well as the completed
    /// referenced tree.
    pub fn insert_commit(&mut self, id: Oid) -> Result<(), Error> {
        unsafe {
            try_call!(raw::git_packbuilder_insert_commit(self.raw, id.raw()));
        }
        Ok(())
    }

    /// Insert objects as given by the walk. Those commits and all objects they
    /// reference will be inserted into the packbuilder.
    pub fn insert_walk(&mut self, walk: &mut Revwalk<'_>) -> Result<(), Error> {
        unsafe {
            try_call!(raw::git_packbuilder_insert_walk(self.raw, walk.raw()));
        }
        Ok(())
    }

    /// Recursively insert an object and its referenced objects. Insert the
    /// object as well as any object it references.
    pub fn insert_recursive(&mut self, id: Oid, name: Option<&str>) -> Result<(), Error> {
        let name = crate::opt_cstr(name)?;
        unsafe {
            try_call!(raw::git_packbuilder_insert_recur(self.raw, id.raw(), name));
        }
        Ok(())
    }

    /// Write the contents of the packfile to an in-memory buffer. The contents
    /// of the buffer will become a valid packfile, even though there will be
    /// no attached index.
    pub fn write_buf(&mut self, buf: &mut Buf) -> Result<(), Error> {
        unsafe {
            try_call!(raw::git_packbuilder_write_buf(buf.raw(), self.raw));
        }
        Ok(())
    }

    /// Create the new pack and pass each object to the callback.
    pub fn foreach<F>(&mut self, mut cb: F) -> Result<(), Error>
    where
        F: FnMut(&[u8]) -> bool,
    {
        let mut cb = &mut cb as &mut ForEachCb<'_>;
        let ptr = &mut cb as *mut _;
        unsafe {
            try_call!(raw::git_packbuilder_foreach(
                self.raw,
                foreach_c,
                ptr as *mut _
            ));
        }
        Ok(())
    }

    /// `progress` will be called with progress information during pack
    /// building. Be aware that this is called inline with pack building
    /// operations, so performance may be affected.
    ///
    /// There can only be one progress callback attached, this will replace any
    /// existing one. See `unset_progress_callback` to remove the current
    /// progress callback without attaching a new one.
    pub fn set_progress_callback<F>(&mut self, progress: F) -> Result<(), Error>
    where
        F: FnMut(PackBuilderStage, u32, u32) -> bool + 'repo,
    {
        let mut progress = Box::new(Box::new(progress) as Box<ProgressCb<'_>>);
        let ptr = &mut *progress as *mut _;
        let progress_c = Some(progress_c as raw::git_packbuilder_progress);
        unsafe {
            try_call!(raw::git_packbuilder_set_callbacks(
                self.raw,
                progress_c,
                ptr as *mut _
            ));
        }
        self.progress = Some(progress);
        Ok(())
    }

    /// Remove the current progress callback.  See `set_progress_callback` to
    /// set the progress callback.
    pub fn unset_progress_callback(&mut self) -> Result<(), Error> {
        unsafe {
            try_call!(raw::git_packbuilder_set_callbacks(
                self.raw,
                None,
                ptr::null_mut()
            ));
            self.progress = None;
        }
        Ok(())
    }

    /// Set the number of threads to be used.
    ///
    /// Returns the number of threads to be used.
    pub fn set_threads(&mut self, threads: u32) -> u32 {
        unsafe { raw::git_packbuilder_set_threads(self.raw, threads) }
    }

    /// Get the total number of objects the packbuilder will write out.
    pub fn object_count(&self) -> usize {
        unsafe { raw::git_packbuilder_object_count(self.raw) }
    }

    /// Get the number of objects the packbuilder has already written out.
    pub fn written(&self) -> usize {
        unsafe { raw::git_packbuilder_written(self.raw) }
    }

    /// Get the packfile's hash. A packfile's name is derived from the sorted
    /// hashing of all object names. This is only correct after the packfile
    /// has been written.
    pub fn hash(&self) -> Option<Oid> {
        if self.object_count() == 0 {
            unsafe { Some(Binding::from_raw(raw::git_packbuilder_hash(self.raw))) }
        } else {
            None
        }
    }
}

impl<'repo> Binding for PackBuilder<'repo> {
    type Raw = *mut raw::git_packbuilder;
    unsafe fn from_raw(ptr: *mut raw::git_packbuilder) -> PackBuilder<'repo> {
        PackBuilder {
            raw: ptr,
            progress: None,
            _marker: marker::PhantomData,
        }
    }
    fn raw(&self) -> *mut raw::git_packbuilder {
        self.raw
    }
}

impl<'repo> Drop for PackBuilder<'repo> {
    fn drop(&mut self) {
        unsafe {
            raw::git_packbuilder_set_callbacks(self.raw, None, ptr::null_mut());
            raw::git_packbuilder_free(self.raw);
        }
    }
}

impl Binding for PackBuilderStage {
    type Raw = raw::git_packbuilder_stage_t;
    unsafe fn from_raw(raw: raw::git_packbuilder_stage_t) -> PackBuilderStage {
        match raw {
            raw::GIT_PACKBUILDER_ADDING_OBJECTS => PackBuilderStage::AddingObjects,
            raw::GIT_PACKBUILDER_DELTAFICATION => PackBuilderStage::Deltafication,
            _ => panic!("Unknown git diff binary kind"),
        }
    }
    fn raw(&self) -> raw::git_packbuilder_stage_t {
        match *self {
            PackBuilderStage::AddingObjects => raw::GIT_PACKBUILDER_ADDING_OBJECTS,
            PackBuilderStage::Deltafication => raw::GIT_PACKBUILDER_DELTAFICATION,
        }
    }
}

extern "C" fn foreach_c(buf: *const c_void, size: size_t, data: *mut c_void) -> c_int {
    unsafe {
        let buf = slice::from_raw_parts(buf as *const u8, size as usize);

        let r = panic::wrap(|| {
            let data = data as *mut &mut ForEachCb<'_>;
            (*data)(buf)
        });
        if r == Some(true) {
            0
        } else {
            -1
        }
    }
}

extern "C" fn progress_c(
    stage: raw::git_packbuilder_stage_t,
    current: c_uint,
    total: c_uint,
    data: *mut c_void,
) -> c_int {
    unsafe {
        let stage = Binding::from_raw(stage);

        let r = panic::wrap(|| {
            let data = data as *mut Box<ProgressCb<'_>>;
            (*data)(stage, current, total)
        });
        if r == Some(true) {
            0
        } else {
            -1
        }
    }
}

#[cfg(test)]
mod tests {
    use crate::{Buf, Oid, Repository};
    use std::fs::File;
    use std::path::Path;

    fn commit(repo: &Repository) -> (Oid, Oid) {
        let mut index = t!(repo.index());
        let root = repo.path().parent().unwrap();
        t!(File::create(&root.join("foo")));
        t!(index.add_path(Path::new("foo")));

        let tree_id = t!(index.write_tree());
        let tree = t!(repo.find_tree(tree_id));
        let sig = t!(repo.signature());
        let head_id = t!(repo.refname_to_id("HEAD"));
        let parent = t!(repo.find_commit(head_id));
        let commit = t!(repo.commit(Some("HEAD"), &sig, &sig, "commit", &tree, &[&parent]));
        (commit, tree_id)
    }

    fn pack_header(len: u8) -> Vec<u8> {
        [].iter()
            .chain(b"PACK") // signature
            .chain(&[0, 0, 0, 2]) // version number
            .chain(&[0, 0, 0, len]) // number of objects
            .cloned()
            .collect::<Vec<u8>>()
    }

    fn empty_pack_header() -> Vec<u8> {
        pack_header(0)
            .iter()
            .chain(&[
                0x02, 0x9d, 0x08, 0x82, 0x3b, // ^
                0xd8, 0xa8, 0xea, 0xb5, 0x10, // | SHA-1 of the zero
                0xad, 0x6a, 0xc7, 0x5c, 0x82, // | object pack header
                0x3c, 0xfd, 0x3e, 0xd3, 0x1e,
            ]) // v
            .cloned()
            .collect::<Vec<u8>>()
    }

    #[test]
    fn smoke() {
        let (_td, repo) = crate::test::repo_init();
        let _builder = t!(repo.packbuilder());
    }

    #[test]
    fn smoke_write_buf() {
        let (_td, repo) = crate::test::repo_init();
        let mut builder = t!(repo.packbuilder());
        let mut buf = Buf::new();
        t!(builder.write_buf(&mut buf));
        assert!(builder.hash().unwrap().is_zero());
        assert_eq!(&*buf, &*empty_pack_header());
    }

    #[test]
    fn smoke_foreach() {
        let (_td, repo) = crate::test::repo_init();
        let mut builder = t!(repo.packbuilder());
        let mut buf = Vec::<u8>::new();
        t!(builder.foreach(|bytes| {
            buf.extend(bytes);
            true
        }));
        assert_eq!(&*buf, &*empty_pack_header());
    }

    #[test]
    fn insert_write_buf() {
        let (_td, repo) = crate::test::repo_init();
        let mut builder = t!(repo.packbuilder());
        let mut buf = Buf::new();
        let (commit, _tree) = commit(&repo);
        t!(builder.insert_object(commit, None));
        assert_eq!(builder.object_count(), 1);
        t!(builder.write_buf(&mut buf));
        // Just check that the correct number of objects are written
        assert_eq!(&buf[0..12], &*pack_header(1));
    }

    #[test]
    fn insert_tree_write_buf() {
        let (_td, repo) = crate::test::repo_init();
        let mut builder = t!(repo.packbuilder());
        let mut buf = Buf::new();
        let (_commit, tree) = commit(&repo);
        // will insert the tree itself and the blob, 2 objects
        t!(builder.insert_tree(tree));
        assert_eq!(builder.object_count(), 2);
        t!(builder.write_buf(&mut buf));
        // Just check that the correct number of objects are written
        assert_eq!(&buf[0..12], &*pack_header(2));
    }

    #[test]
    fn insert_commit_write_buf() {
        let (_td, repo) = crate::test::repo_init();
        let mut builder = t!(repo.packbuilder());
        let mut buf = Buf::new();
        let (commit, _tree) = commit(&repo);
        // will insert the commit, its tree and the blob, 3 objects
        t!(builder.insert_commit(commit));
        assert_eq!(builder.object_count(), 3);
        t!(builder.write_buf(&mut buf));
        // Just check that the correct number of objects are written
        assert_eq!(&buf[0..12], &*pack_header(3));
    }

    #[test]
    fn progress_callback() {
        let mut progress_called = false;
        {
            let (_td, repo) = crate::test::repo_init();
            let mut builder = t!(repo.packbuilder());
            let (commit, _tree) = commit(&repo);
            t!(builder.set_progress_callback(|_, _, _| {
                progress_called = true;
                true
            }));
            t!(builder.insert_commit(commit));
            t!(builder.write_buf(&mut Buf::new()));
        }
        assert_eq!(progress_called, true);
    }

    #[test]
    fn clear_progress_callback() {
        let mut progress_called = false;
        {
            let (_td, repo) = crate::test::repo_init();
            let mut builder = t!(repo.packbuilder());
            let (commit, _tree) = commit(&repo);
            t!(builder.set_progress_callback(|_, _, _| {
                progress_called = true;
                true
            }));
            t!(builder.unset_progress_callback());
            t!(builder.insert_commit(commit));
            t!(builder.write_buf(&mut Buf::new()));
        }
        assert_eq!(progress_called, false);
    }

    #[test]
    fn set_threads() {
        let (_td, repo) = crate::test::repo_init();
        let mut builder = t!(repo.packbuilder());
        let used = builder.set_threads(4);
        // Will be 1 if not compiled with threading.
        assert!(used == 1 || used == 4);
    }
}