X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=scandir.cc;h=71fba9dc22fcbc597303e44ceeac16a54048da4e;hb=248b2455853ed082bf3b032fea4cb6b557a145ae;hp=30b8d4572aa6eab67a9796018f8ba8c59310e6a4;hpb=738a672b1a4a95eb24b785c9238594de99f8e314;p=cumulus.git diff --git a/scandir.cc b/scandir.cc index 30b8d45..71fba9d 100644 --- a/scandir.cc +++ b/scandir.cc @@ -1,27 +1,32 @@ /* Recursively descend the filesystem and visit each file. */ -#include -#include -#include #include #include #include -#include +#include +#include +#include +#include +#include +#include #include +#include #include #include -#include -#include -#include -#include #include -#include +#include +#include #include +#include +#include +#include #include "format.h" +#include "localdb.h" #include "store.h" #include "sha1.h" +#include "statcache.h" using std::list; using std::string; @@ -36,6 +41,14 @@ static char *block_buf; static const size_t LBS_METADATA_BLOCK_SIZE = 65536; +/* Local database, which tracks objects written in this and previous + * invocations to help in creating incremental snapshots. */ +LocalDb *db; + +/* Stat cache, which stored data locally to speed the backup process by quickly + * skipping files which have not changed. */ +StatCache *statcache; + /* Contents of the root object. This will contain a set of indirect links to * the metadata objects. */ std::ostringstream metadata_root; @@ -48,6 +61,9 @@ std::set segment_list; void scandir(const string& path); +/* Selection of files to include/exclude in the snapshot. */ +std::list excludes; + /* Ensure contents of metadata are flushed to an object. */ void metadata_flush() { @@ -57,7 +73,7 @@ void metadata_flush() /* Write current metadata information to a new object. */ LbsObject *meta = new LbsObject; - meta->set_group("root"); + meta->set_group("metadata"); meta->set_data(m.data(), m.size()); meta->write(tss); meta->checksum(); @@ -98,8 +114,9 @@ size_t file_read(int fd, char *buf, size_t maxlen) } /* Read the contents of a file (specified by an open file descriptor) and copy - * the data to the store. */ -void dumpfile(int fd, dictionary &file_info) + * the data to the store. Returns the size of the file (number of bytes + * dumped), or -1 on error. */ +int64_t dumpfile(int fd, dictionary &file_info, const string &path) { struct stat stat_buf; fstat(fd, &stat_buf); @@ -108,7 +125,7 @@ void dumpfile(int fd, dictionary &file_info) if ((stat_buf.st_mode & S_IFMT) != S_IFREG) { fprintf(stderr, "file is no longer a regular file!\n"); - return; + return -1; } /* The index data consists of a sequence of pointers to the data blocks @@ -123,20 +140,50 @@ void dumpfile(int fd, dictionary &file_info) hash.process(block_buf, bytes); - // tarstore processing - LbsObject *o = new LbsObject; - o->set_group("data"); - o->set_data(block_buf, bytes); - o->write(tss); - object_list.push_back(o->get_name()); - segment_list.insert(o->get_ref().get_segment()); - delete o; + // Either find a copy of this block in an already-existing segment, or + // index it so it can be re-used in the future + double block_age = 0.0; + SHA1Checksum block_hash; + block_hash.process(block_buf, bytes); + string block_csum = block_hash.checksum_str(); + ObjectReference ref = db->FindObject(block_csum, bytes); + + // Store a copy of the object if one does not yet exist + if (ref.get_segment().size() == 0) { + LbsObject *o = new LbsObject; + + /* We might still have seen this checksum before, if the object was + * stored at some time in the past, but we have decided to clean + * the segment the object was originally stored in (FindObject will + * not return such objects). When rewriting the object contents, + * put it in a separate group, so that old objects get grouped + * together. The hope is that these old objects will continue to + * be used in the future, and we obtain segments which will + * continue to be well-utilized. Additionally, keep track of the + * age of the data by looking up the age of the block which was + * expired and using that instead of the current time. */ + if (db->IsOldObject(block_csum, bytes, &block_age)) + o->set_group("compacted"); + else + o->set_group("data"); + + o->set_data(block_buf, bytes); + o->write(tss); + ref = o->get_ref(); + db->StoreObject(ref, block_csum, bytes, block_age); + delete o; + } + object_list.push_back(ref.to_string()); + segment_list.insert(ref.get_segment()); + db->UseObject(ref); size += bytes; } file_info["checksum"] = hash.checksum_str(); + statcache->Save(path, &stat_buf, file_info["checksum"], object_list); + /* For files that only need to be broken apart into a few objects, store * the list of objects directly. For larger files, store the data * out-of-line and provide a pointer to the indrect object. */ @@ -157,13 +204,15 @@ void dumpfile(int fd, dictionary &file_info) } LbsObject *i = new LbsObject; - i->set_group("indirect"); + i->set_group("metadata"); i->set_data(blocklist.data(), blocklist.size()); i->write(tss); file_info["data"] = "@" + i->get_name(); segment_list.insert(i->get_ref().get_segment()); delete i; } + + return size; } void scanfile(const string& path) @@ -173,26 +222,43 @@ void scanfile(const string& path) struct stat stat_buf; char *buf; ssize_t len; + int64_t file_size; list refs; // Set to true if the item is a directory and we should recursively scan bool recurse = false; + // Check this file against the include/exclude list to see if it should be + // considered + for (list::iterator i = excludes.begin(); + i != excludes.end(); ++i) { + if (path == *i) { + printf("Excluding %s\n", path.c_str()); + return; + } + } + dictionary file_info; lstat(path.c_str(), &stat_buf); printf("%s\n", path.c_str()); - metadata << "name: " << uri_encode(path) << "\n"; - file_info["mode"] = encode_int(stat_buf.st_mode & 07777); - file_info["atime"] = encode_int(stat_buf.st_atime); - file_info["ctime"] = encode_int(stat_buf.st_ctime); file_info["mtime"] = encode_int(stat_buf.st_mtime); file_info["user"] = encode_int(stat_buf.st_uid); file_info["group"] = encode_int(stat_buf.st_gid); + struct passwd *pwd = getpwuid(stat_buf.st_uid); + if (pwd != NULL) { + file_info["user"] += " (" + uri_encode(pwd->pw_name) + ")"; + } + + struct group *grp = getgrgid(stat_buf.st_gid); + if (pwd != NULL) { + file_info["group"] += " (" + uri_encode(grp->gr_name) + ")"; + } + char inode_type; switch (stat_buf.st_mode & S_IFMT) { @@ -240,18 +306,34 @@ void scanfile(const string& path) * - O_NONBLOCK: prevents open() from blocking if the file was * replaced by a fifo * We also add in O_NOATIME, since this may reduce disk writes (for - * inode updates). */ + * inode updates). However, O_NOATIME may result in EPERM, so if the + * initial open fails, try again without O_NOATIME. */ fd = open(path.c_str(), O_RDONLY|O_NOATIME|O_NOFOLLOW|O_NONBLOCK); + if (fd < 0) { + fd = open(path.c_str(), O_RDONLY|O_NOFOLLOW|O_NONBLOCK); + } + if (fd < 0) { + fprintf(stderr, "Unable to open file %s: %m\n", path.c_str()); + return; + } /* Drop the use of the O_NONBLOCK flag; we only wanted that for file * open. */ flags = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, flags & ~O_NONBLOCK); - file_info["size"] = encode_int(stat_buf.st_size); - dumpfile(fd, file_info); + file_size = dumpfile(fd, file_info, path); + file_info["size"] = encode_int(file_size); close(fd); + if (file_size < 0) + return; // error occurred; do not dump file + + if (file_size != stat_buf.st_size) { + fprintf(stderr, "Warning: Size of %s changed during reading\n", + path.c_str()); + } + break; case S_IFDIR: inode_type = 'd'; @@ -265,6 +347,7 @@ void scanfile(const string& path) file_info["type"] = string(1, inode_type); + metadata << "name: " << uri_encode(path) << "\n"; dict_output(metadata, file_info); metadata << "\n"; @@ -301,25 +384,109 @@ void scandir(const string& path) for (vector::iterator i = contents.begin(); i != contents.end(); ++i) { const string& filename = *i; - scanfile(path + "/" + filename); + if (path == ".") + scanfile(filename); + else + scanfile(path + "/" + filename); } closedir(dir); } -int main(int argc, char *argv[]) +void usage(const char *program) { - block_buf = new char[LBS_BLOCK_SIZE]; + fprintf(stderr, + "Usage: %s [OPTION]... SOURCE DEST\n" + "Produce backup snapshot of files in SOURCE and store to DEST.\n" + "\n" + "Options:\n" + " --exclude=PATH exclude files in PATH from snapshot\n" + " --localdb=PATH local backup metadata is stored in PATH\n", + program); +} +int main(int argc, char *argv[]) +{ + string backup_source = "."; string backup_dest = "."; + string localdb_dir = ""; + + while (1) { + static struct option long_options[] = { + {"localdb", 1, 0, 0}, // 0 + {"exclude", 1, 0, 0}, // 1 + {"filter", 1, 0, 0}, // 2 + {"filter-extension", 1, 0, 0}, // 3 + {NULL, 0, 0, 0}, + }; - if (argc > 1) - backup_dest = argv[1]; + int long_index; + int c = getopt_long(argc, argv, "", long_options, &long_index); + + if (c == -1) + break; + + if (c == 0) { + switch (long_index) { + case 0: // --localdb + localdb_dir = optarg; + break; + case 1: // --exclude + excludes.push_back(optarg); + break; + case 2: // --filter + filter_program = optarg; + break; + case 3: // --filter-extension + filter_extension = optarg; + break; + default: + fprintf(stderr, "Unhandled long option!\n"); + return 1; + } + } else { + usage(argv[0]); + return 1; + } + } + + if (argc < optind + 2) { + usage(argv[0]); + return 1; + } + + backup_source = argv[optind]; + backup_dest = argv[argc - 1]; + + if (localdb_dir == "") { + localdb_dir = backup_dest; + } + + printf("Source: %s\nDest: %s\nDatabase: %s\n\n", + backup_source.c_str(), backup_dest.c_str(), localdb_dir.c_str()); tss = new TarSegmentStore(backup_dest); + block_buf = new char[LBS_BLOCK_SIZE]; - string desc_filename = backup_dest + "/snapshot.lbs"; - std::ofstream descriptor(desc_filename.c_str()); + /* Store the time when the backup started, so it can be included in the + * snapshot name. */ + time_t now; + struct tm time_buf; + char desc_buf[256]; + time(&now); + localtime_r(&now, &time_buf); + strftime(desc_buf, sizeof(desc_buf), "%Y%m%dT%H%M%S", &time_buf); + + /* Open the local database which tracks all objects that are stored + * remotely, for efficient incrementals. Provide it with the name of this + * snapshot. */ + string database_path = localdb_dir + "/localdb.sqlite"; + db = new LocalDb; + db->Open(database_path.c_str(), desc_buf); + + /* Initialize the stat cache, for skipping over unchanged files. */ + statcache = new StatCache; + statcache->Open(localdb_dir.c_str(), desc_buf); try { scanfile("."); @@ -331,22 +498,36 @@ int main(int argc, char *argv[]) const string md = metadata_root.str(); LbsObject *root = new LbsObject; - root->set_group("root"); + root->set_group("metadata"); root->set_data(md.data(), md.size()); root->write(tss); root->checksum(); - segment_list.insert(root->get_ref().get_segment()); - descriptor << "root: " << root->get_ref().to_string() << "\n\n"; + + /* Write a backup descriptor file, which says which segments are needed and + * where to start to restore this snapshot. The filename is based on the + * current time. */ + string desc_filename = backup_dest + "/snapshot-" + desc_buf + ".lbs"; + std::ofstream descriptor(desc_filename.c_str()); + + descriptor << "Format: LBS Snapshot v0.1\n"; + strftime(desc_buf, sizeof(desc_buf), "%Y-%m-%d %H:%M:%S %z", &time_buf); + descriptor << "Date: " << desc_buf << "\n"; + descriptor << "Root: " << root->get_ref().to_string() << "\n"; delete root; - descriptor << "segments:\n"; + descriptor << "Segments:\n"; for (std::set::iterator i = segment_list.begin(); i != segment_list.end(); ++i) { descriptor << " " << *i << "\n"; } + db->Close(); + + statcache->Close(); + delete statcache; + tss->sync(); delete tss;