Implement rudimentary checkout operations

1 files changed, 82 insertions, 0 deletions

diff --git a/checkout.go b/checkout.go
new file mode 100644
index 0000000..bbeb240
--- /dev/null
+++ b/checkout.go
@@ -0,0 +1,82 @@
+package git
+
+/*
+#cgo pkg-config: libgit2
+#include <git2.h>
+git_checkout_opts git_checkout_opts_init() {
+	git_checkout_opts ret = GIT_CHECKOUT_OPTS_INIT;
+	return ret;
+}
+*/
+import "C"
+import (
+	"os"
+)
+
+type CheckoutStrategy uint
+
+const (
+	CHECKOUT_NONE                         CheckoutStrategy = C.GIT_CHECKOUT_NONE                         // Dry run, no actual updates
+	CHECKOUT_SAFE                                          = C.GIT_CHECKOUT_SAFE                         // Allow safe updates that cannot overwrite uncommitted data
+	CHECKOUT_SAFE_CREATE                                   = C.GIT_CHECKOUT_SAFE_CREATE                  // Allow safe updates plus creation of missing files
+	CHECKOUT_FORCE                                         = C.GIT_CHECKOUT_FORCE                        // Allow all updates to force working directory to look like index
+	CHECKOUT_ALLOW_CONFLICTS                               = C.GIT_CHECKOUT_ALLOW_CONFLICTS              // Allow checkout to make safe updates even if conflicts are found
+	CHECKOUT_REMOVE_UNTRACKED                              = C.GIT_CHECKOUT_REMOVE_UNTRACKED             // Remove untracked files not in index (that are not ignored)
+	CHECKOUT_REMOVE_IGNORED                                = C.GIT_CHECKOUT_REMOVE_IGNORED               // Remove ignored files not in index
+	CHECKOUT_UPDATE_ONLY                                   = C.GIT_CHECKOUT_UPDATE_ONLY                  // Only update existing files, don't create new ones
+	CHECKOUT_DONT_UPDATE_INDEX                             = C.GIT_CHECKOUT_DONT_UPDATE_INDEX            // Normally checkout updates index entries as it goes; this stops that
+	CHECKOUT_NO_REFRESH                                    = C.GIT_CHECKOUT_NO_REFRESH                   // Don't refresh index/config/etc before doing checkout
+	CHECKOUT_DISABLE_PATHSPEC_MATCH                        = C.GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH       // Treat pathspec as simple list of exact match file paths
+	CHECKOUT_SKIP_UNMERGED                                 = C.GIT_CHECKOUT_SKIP_UNMERGED                // Allow checkout to skip unmerged files (NOT IMPLEMENTED)
+	CHECKOUT_USE_OURS                                      = C.GIT_CHECKOUT_USE_OURS                     // For unmerged files, checkout stage 2 from index (NOT IMPLEMENTED)
+	CHECKOUT_USE_THEIRS                                    = C.GIT_CHECKOUT_USE_THEIRS                   // For unmerged files, checkout stage 3 from index (NOT IMPLEMENTED)
+	CHECKOUT_UPDATE_SUBMODULES                             = C.GIT_CHECKOUT_UPDATE_SUBMODULES            // Recursively checkout submodules with same options (NOT IMPLEMENTED)
+	CHECKOUT_UPDATE_SUBMODULES_IF_CHANGED                  = C.GIT_CHECKOUT_UPDATE_SUBMODULES_IF_CHANGED // Recursively checkout submodules if HEAD moved in super repo (NOT IMPLEMENTED)
+)
+
+type CheckoutOpts struct {
+	Strategy       CheckoutStrategy // Default will be a dry run
+	DisableFilters bool				// Don't apply filters like CRLF conversion
+	DirMode        os.FileMode		// Default is 0755
+	FileMode       os.FileMode		// Default is 0644 or 0755 as dictated by blob
+	FileOpenFlags  int				// Default is O_CREAT | O_TRUNC | O_WRONLY
+}
+
+// Convert the CheckoutOpts struct to the corresponding C-struct
+func populateCheckoutOpts(ptr *C.git_checkout_opts, opts *CheckoutOpts) {
+	*ptr = C.git_checkout_opts_init()
+	if opts == nil {
+		return
+	}
+	ptr.checkout_strategy = C.uint(opts.Strategy)
+	ptr.disable_filters = cbool(opts.DisableFilters)
+	ptr.dir_mode = C.uint(opts.DirMode.Perm())
+	ptr.file_mode = C.uint(opts.FileMode.Perm())
+}
+
+// Updates files in the index and the working tree to match the content of
+// the commit pointed at by HEAD.
+func (v *Repository) Checkout(opts *CheckoutOpts) error {
+	var copts C.git_checkout_opts
+	populateCheckoutOpts(&copts, opts)
+
+	ret := C.git_checkout_head(v.ptr, &copts)
+	if ret < 0 {
+		return LastError()
+	}
+
+	return nil
+}
+
+// Updates files in the working tree to match the content of the index.
+func (v *Repository) CheckoutIndex(index *Index, opts *CheckoutOpts) error {
+	var copts C.git_checkout_opts
+	populateCheckoutOpts(&copts, opts)
+
+	ret := C.git_checkout_index(v.ptr, index.ptr, &copts)
+	if ret < 0 {
+		return LastError()
+	}
+
+	return nil
+}