X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=scandir.cc;h=e25352794c1a28c004d073150672170013ee2759;hb=15f7cef45e82e54a039e5486f08134c4f9a05471;hp=043d35eeba637f2cba740c7ae0ef0d5ac5d96596;hpb=358b7ac6f741088838fb84979c9127976eb34fdf;p=cumulus.git diff --git a/scandir.cc b/scandir.cc index 043d35e..e253527 100644 --- a/scandir.cc +++ b/scandir.cc @@ -25,6 +25,10 @@ static OutputStream *info_dump = NULL; static SegmentPartitioner *index_segment, *data_segment; +/* Buffer for holding a single block of data read from a file. */ +static const int LBS_BLOCK_SIZE = 1024 * 1024; +static char *block_buf; + void scandir(const string& path); /* Converts time to microseconds since the epoch. */ @@ -33,39 +37,77 @@ int64_t encode_time(time_t time) return (int64_t)time * 1000000; } +/* Read data from a file descriptor and return the amount of data read. A + * short read (less than the requested size) will only occur if end-of-file is + * hit. */ +size_t file_read(int fd, char *buf, size_t maxlen) +{ + size_t bytes_read = 0; + + while (true) { + ssize_t res = read(fd, buf, maxlen); + if (res < 0) { + if (errno == EINTR) + continue; + throw IOException("file_read: error reading"); + } else if (res == 0) { + break; + } else { + bytes_read += res; + buf += res; + maxlen -= res; + } + } + + return bytes_read; +} + +/* 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) { struct stat stat_buf; fstat(fd, &stat_buf); int64_t size = 0; - char buf[4096]; - if ((stat_buf.st_mode & S_IFMT) != S_IFREG) { printf("file is no longer a regular file!\n"); return; } + /* The index data consists of a sequence of pointers to the data blocks + * that actually comprise the file data. This level of indirection is used + * so that the same data block can be used in multiple files, or multiple + * versions of the same file. */ + struct uuid segment_uuid; + int object_id; + OutputStream *index_data = index_segment->new_object(&segment_uuid, + &object_id, + "DREF"); + SHA1Checksum hash; while (true) { - ssize_t res = read(fd, buf, sizeof(buf)); - if (res < 0) { - if (errno == EINTR) - continue; - printf("Error while reading: %m\n"); - return; - } else if (res == 0) { + struct uuid block_segment_uuid; + int block_object_id; + + size_t bytes = file_read(fd, block_buf, LBS_BLOCK_SIZE); + if (bytes == 0) break; - } else { - hash.process(buf, res); - OutputStream *block = data_segment->new_object(); - block->write(buf, res); - size += res; - } + + hash.process(block_buf, bytes); + OutputStream *block = data_segment->new_object(&block_segment_uuid, + &block_object_id, + "DATA"); + block->write(block_buf, bytes); + index_data->write_uuid(block_segment_uuid); + index_data->write_u32(block_object_id); + + size += bytes; } file_info["sha1"] = string((const char *)hash.checksum(), hash.checksum_size()); + file_info["data"] = encode_objref(segment_uuid, object_id); } void scanfile(const string& path) @@ -206,9 +248,11 @@ void scandir(const string& path) int main(int argc, char *argv[]) { + block_buf = new char[LBS_BLOCK_SIZE]; + segment_store = new SegmentStore("."); SegmentWriter *sw = segment_store->new_segment(); - info_dump = sw->new_object(); + info_dump = sw->new_object(NULL, "ROOT"); index_segment = new SegmentPartitioner(segment_store); data_segment = new SegmentPartitioner(segment_store);