examples: add ls-remote, fetch and index-pack examples

Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>

1 files changed, 127 insertions, 0 deletions

diff --git a/examples/network/fetch.c b/examples/network/fetch.c
new file mode 100644
index 000000000..dd732f22e
--- /dev/null
+++ b/examples/network/fetch.c
@@ -0,0 +1,127 @@
+#include "common.h"
+#include <git2.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static void show_refs(git_headarray *refs)
+{
+  int i;
+  git_remote_head *head;
+
+  if(refs->len == 0)
+    puts("Everything up-to-date");
+
+  for(i = 0; i < refs->len; ++i){
+	  char oid[GIT_OID_HEXSZ + 1] = {0};
+	  char *havewant;
+	  head = refs->heads[i];
+	  git_oid_fmt(oid, &head->oid);
+	  printf("%s\t%s\n", oid, head->name);
+  }
+}
+
+static int rename_packfile(char *packname, git_indexer *idx)
+{
+  char path[GIT_PATH_MAX], oid[GIT_OID_HEXSZ + 1], *slash;
+  int ret;
+
+  strcpy(path, packname);
+  slash = strrchr(path, '/');
+
+  if (!slash)
+	  return GIT_EINVALIDARGS;
+
+  memset(oid, 0x0, sizeof(oid));
+  // The name of the packfile is given by it's hash which you can get
+  // with git_indexer_hash after the index has been written out to
+  // disk. Rename the packfile to its "real" name in the same
+  // directory as it was originally (libgit2 stores it in the folder
+  // where the packs go, so a rename in place is the right thing to do here
+  git_oid_fmt(oid, git_indexer_hash(idx));
+  ret = sprintf(slash + 1, "pack-%s.pack", oid);
+  if(ret < 0)
+	  return GIT_EOSERR;
+
+  printf("Renaming pack to %s\n", path);
+  return rename(packname, path);
+}
+
+int fetch(git_repository *repo, int argc, char **argv)
+{
+  git_remote *remote = NULL;
+  git_config *cfg = NULL;
+  git_indexer *idx = NULL;
+  git_indexer_stats stats;
+  int error;
+  char *packname = NULL;
+
+  // Load the repository's configuration
+  error = git_repository_config(&cfg, repo, NULL, NULL);
+  if (error < GIT_SUCCESS)
+    return error;
+
+  // Get the remote and connect to it
+  printf("Fetching %s\n", argv[1]);
+  error = git_remote_get(&remote, cfg, argv[1]);
+  if (error < GIT_SUCCESS)
+    return error;
+
+  error = git_remote_connect(remote, GIT_DIR_FETCH);
+  if (error < GIT_SUCCESS)
+    return error;
+
+  // Perform the packfile negotiation. This is where the two ends
+  // figure out the minimal amount of data that should be transmitted
+  // to bring the repository up-to-date
+  error = git_remote_negotiate(remote);
+  if (error < GIT_SUCCESS)
+    return error;
+
+  // Download the packfile from the server. As we don't know its hash
+  // yet, it will get a temporary filename
+  error = git_remote_download(&packname, remote);
+  if (error < GIT_SUCCESS)
+    return error;
+
+  // No error and a NULL packname means no packfile was needed
+  if (packname != NULL) {
+	  printf("The packname is %s\n", packname);
+
+	  // Create a new instance indexer
+	  error = git_indexer_new(&idx, packname);
+	  if (error < GIT_SUCCESS)
+		  return error;
+
+	  // This should be run in paralel, but it'd be too complicated for the example
+	  error = git_indexer_run(idx, &stats);
+	  if (error < GIT_SUCCESS)
+		  return error;
+
+	  printf("Received %d objects\n", stats.total);
+
+	  // Write the index file. The index will be stored with the
+	  // correct filename
+	  error = git_indexer_write(idx);
+	  if (error < GIT_SUCCESS)
+		  return error;
+
+	  error = rename_packfile(packname, idx);
+	  if (error < GIT_SUCCESS)
+		  return error;
+  }
+
+  // Update the references in the remote's namespace to point to the
+  // right commits. This may be needed even if there was no packfile
+  // to download, which can happen e.g. when the branches have been
+  // changed but all the neede objects are available locally.
+  error = git_remote_update_tips(remote);
+  if (error < GIT_SUCCESS)
+    return error;
+
+  free(packname);
+  git_indexer_free(idx);
+  git_remote_free(remote);
+
+  return GIT_SUCCESS;
+}