Upcoming support for clustered databases will need to provide a more abstract way to determine when a given file should be compacted, so this changes the standalone database support to use this mechanism in advance.
Signed-off-by: Ben Pfaff <[email protected]> --- ovsdb/file.c | 24 ++++++++---------------- ovsdb/log.c | 26 +++++++++++++++++++------- ovsdb/log.h | 22 +++++++++++++++++++++- 3 files changed, 48 insertions(+), 24 deletions(-) diff --git a/ovsdb/file.c b/ovsdb/file.c index fca07c3d722d..094fa0ce207a 100644 --- a/ovsdb/file.c +++ b/ovsdb/file.c @@ -73,7 +73,6 @@ static struct ovsdb_error *ovsdb_file_create(struct ovsdb *, struct ovsdb_log *, const char *file_name, unsigned int n_transactions, - off_t snapshot_size, struct ovsdb_file **filep); /* Opens database 'file_name' and stores a pointer to the new database in @@ -209,7 +208,6 @@ ovsdb_file_open__(const char *file_name, * * The schema precedes the snapshot in the log; we could compensate for its * size, but it's just not that important. */ - off_t snapshot_size = 0; unsigned int n_transactions = 0; while ((error = ovsdb_log_read(log, &json)) == NULL && json) { struct ovsdb_txn *txn; @@ -230,7 +228,7 @@ ovsdb_file_open__(const char *file_name, } if (n_transactions == 1) { - snapshot_size = ovsdb_log_get_offset(log); + ovsdb_log_mark_base(log); } } if (error) { @@ -247,8 +245,7 @@ ovsdb_file_open__(const char *file_name, if (!read_only) { struct ovsdb_file *file; - error = ovsdb_file_create(db, log, file_name, n_transactions, - snapshot_size, &file); + error = ovsdb_file_create(db, log, file_name, n_transactions, &file); if (error) { goto error; } @@ -515,7 +512,6 @@ struct ovsdb_file { long long int last_compact; long long int next_compact; unsigned int n_transactions; - off_t snapshot_size; }; static const struct ovsdb_replica_class ovsdb_file_class; @@ -523,8 +519,7 @@ static const struct ovsdb_replica_class ovsdb_file_class; static struct ovsdb_error * ovsdb_file_create(struct ovsdb *db, struct ovsdb_log *log, const char *file_name, - unsigned int n_transactions, off_t snapshot_size, - struct ovsdb_file **filep) + unsigned int n_transactions, struct ovsdb_file **filep) { struct ovsdb_file *file; char *deref_name; @@ -548,7 +543,6 @@ ovsdb_file_create(struct ovsdb *db, struct ovsdb_log *log, file->file_name = abs_name; file->last_compact = time_msec(); file->next_compact = file->last_compact + COMPACT_MIN_MSEC; - file->snapshot_size = snapshot_size; file->n_transactions = n_transactions; ovsdb_add_replica(db, &file->replica); @@ -601,12 +595,9 @@ ovsdb_file_commit(struct ovsdb_replica *replica, * tried), and if there are at least 100 transactions in the database, and * if the database is at least 10 MB, and the database is at least 4x the * size of the previous snapshot, then compact the database. */ - off_t log_size = ovsdb_log_get_offset(file->log); if (time_msec() >= file->next_compact && file->n_transactions >= 100 - && log_size >= 10 * 1024 * 1024 - && log_size / 4 >= file->snapshot_size) - { + && ovsdb_log_has_grown(file->log)) { error = ovsdb_file_compact(file); if (error) { char *s = ovsdb_error_to_string(error); @@ -653,10 +644,9 @@ ovsdb_file_compact(struct ovsdb_file *file) int retval; comment = xasprintf("compacting database online " - "(%.3f seconds old, %u transactions, %llu bytes)", + "(%.3f seconds old, %u transactions)", (time_wall_msec() - file->last_compact) / 1000.0, - file->n_transactions, - (unsigned long long) ovsdb_log_get_offset(file->log)); + file->n_transactions); VLOG_INFO("%s: %s", file->file_name, comment); /* Commit the old version, so that we can be assured that we'll eventually @@ -686,6 +676,7 @@ ovsdb_file_compact(struct ovsdb_file *file) if (error) { goto exit; } + ovsdb_log_mark_base(new_log); /* Replace original file by the temporary file. * @@ -740,6 +731,7 @@ ovsdb_file_compact(struct ovsdb_file *file) ovs_fatal(0, "error reading database"); } json_destroy(json); + ovsdb_log_mark_base(file->log); } /* Success! */ diff --git a/ovsdb/log.c b/ovsdb/log.c index dd641884a2ee..27f4b328d451 100644 --- a/ovsdb/log.c +++ b/ovsdb/log.c @@ -76,6 +76,7 @@ struct ovsdb_log { char *magic; struct lockfile *lockfile; FILE *stream; + off_t base; }; /* Whether the OS supports renaming open files. @@ -243,6 +244,7 @@ ovsdb_log_open(const char *name, const char *magic, file->stream = stream; file->prev_offset = 0; file->offset = 0; + file->base = 0; *filep = file; return NULL; @@ -586,13 +588,21 @@ ovsdb_log_commit(struct ovsdb_log *file) return NULL; } -/* Returns the current offset into the file backing 'log', in bytes. This - * reflects the number of bytes that have been read or written in the file. If - * the whole file has been read, this is the file size. */ -off_t -ovsdb_log_get_offset(const struct ovsdb_log *log) +/* Sets the current position in 'log' as the "base", that is, the initial size + * of the log that ovsdb_log_has_grown() uses to determine whether the log has + * grown enough to make compacting worthwhile. */ +void +ovsdb_log_mark_base(struct ovsdb_log *log) { - return log->offset; + log->base = log->offset; +} + +/* Returns true if 'log' has grown enough above the base that it's worthwhile + * to compact it, false otherwise. */ +bool +ovsdb_log_has_grown(const struct ovsdb_log *log) +{ + return log->offset > 10 * 1024 * 1024 && log->offset / 4 > log->base; } /* Attempts to atomically replace the contents of 'log', on disk, by the 'n' @@ -618,6 +628,7 @@ ovsdb_log_replace(struct ovsdb_log *log, struct json **entries, size_t n) return error; } } + ovsdb_log_mark_base(new); return ovsdb_log_replace_commit(log, new); } @@ -752,7 +763,8 @@ ovsdb_log_replace_commit(struct ovsdb_log *old, struct ovsdb_log *new) old->magic = new->magic; new->magic = NULL; /* Keep old->lockfile. */ - /* stream was already replaced above. */ + old->base = new->base; + /* Free 'new'. */ ovsdb_log_close(new); diff --git a/ovsdb/log.h b/ovsdb/log.h index 4b74ca11ce6a..e68e922f871a 100644 --- a/ovsdb/log.h +++ b/ovsdb/log.h @@ -16,6 +16,25 @@ #ifndef OVSDB_LOG_H #define OVSDB_LOG_H 1 +/* OVSDB log. + * + * A log consists of a series of records. After opening or creating a log with + * ovsdb_log_open(), the client may use ovsdb_log_read() to read any existing + * records, one by one. The client may also use ovsdb_log_write() to write new + * records (if some records have not yet been read at this point, then the + * first write truncates them). + * + * Log writes are atomic. A client may use ovsdb_log_commit() to ensure that + * they are durable. + * + * Logs provide a mechansim to allow the client to tell when they have grown + * enough that compacting may be warranted. After reading existing log + * contents, the client uses ovsdb_log_mark_base() to mark the "base" to be + * considered as the initial size of the log. Thereafter, a client may call + * ovsdb_log_has_grown() to get an indication whether the log has grown enough + * that compacting is advised. + */ + #include <sys/types.h> #include "compiler.h" @@ -53,7 +72,8 @@ struct ovsdb_error *ovsdb_log_write(struct ovsdb_log *, const struct json *) struct ovsdb_error *ovsdb_log_commit(struct ovsdb_log *) OVS_WARN_UNUSED_RESULT; -off_t ovsdb_log_get_offset(const struct ovsdb_log *); +void ovsdb_log_mark_base(struct ovsdb_log *); +bool ovsdb_log_has_grown(const struct ovsdb_log *); struct ovsdb_error *ovsdb_log_replace(struct ovsdb_log *, struct json **entries, size_t n) -- 2.10.2 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
