diff options
Diffstat (limited to 'db2/log/log_put.c')
| -rw-r--r-- | db2/log/log_put.c | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/db2/log/log_put.c b/db2/log/log_put.c new file mode 100644 index 0000000000..db31f9b0e1 --- /dev/null +++ b/db2/log/log_put.c @@ -0,0 +1,484 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1996, 1997 + * Sleepycat Software. All rights reserved. + */ +#include "config.h" + +#ifndef lint +static const char sccsid[] = "@(#)log_put.c 10.12 (Sleepycat) 8/20/97"; +#endif /* not lint */ + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> + +#include <errno.h> +#include <fcntl.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> +#endif + +#include "db_int.h" +#include "shqueue.h" +#include "db_page.h" +#include "log.h" +#include "hash.h" +#include "common_ext.h" + +static int __log_fill __P((DB_LOG *, void *, u_int32_t)); +static int __log_newfd __P((DB_LOG *)); +static int __log_write __P((DB_LOG *, void *, u_int32_t)); +static int __log_putr __P((DB_LOG *, const DBT *, u_int32_t)); + +/* + * log_put -- + * Write a log record. + */ +int +log_put(dblp, lsn, dbt, flags) + DB_LOG *dblp; + DB_LSN *lsn; + const DBT *dbt; + int flags; +{ + int ret; + + /* Validate arguments. */ +#define OKFLAGS (DB_CHECKPOINT | DB_FLUSH) + if (flags != 0) { + if ((ret = + __db_fchk(dblp->dbenv, "log_put", flags, OKFLAGS)) != 0) + return (ret); + switch (flags) { + case DB_CHECKPOINT: + case DB_FLUSH: + case 0: + break; + default: + return (__db_ferr(dblp->dbenv, "log_put", 1)); + } + } + + LOCK_LOGREGION(dblp); + + ret = __log_put(dblp, lsn, dbt, flags); + + UNLOCK_LOGREGION(dblp); + + return (ret); +} + +/* + * __log_put -- + * Write a log record; internal version. + * + * PUBLIC: int __log_put __P((DB_LOG *, DB_LSN *, const DBT *, int)); + */ +int +__log_put(dblp, lsn, dbt, flags) + DB_LOG *dblp; + DB_LSN *lsn; + const DBT *dbt; + int flags; +{ + DBT t; + DBT fid_dbt; + DB_LSN r_unused; + FNAME *fnp; + LOG *lp; + u_int32_t lastoff; + int ret; + + lp = dblp->lp; + + /* If this information won't fit in the file, swap files. */ + if (lp->lsn.offset + sizeof(HDR) + dbt->size > lp->persist.lg_max) { + if (sizeof(HDR) + + sizeof(LOGP) + dbt->size > lp->persist.lg_max) { + __db_err(dblp->dbenv, + "log_put: record larger than maximum file size"); + return (EINVAL); + } + if (lp->b_off != 0) { + if ((ret = __log_write(dblp, lp->buf, lp->b_off)) != 0) + return (ret); + if ((ret = __db_fsync(dblp->lfd)) != 0) + return (ret); + lp->s_lsn.file = lp->lsn.file; + lp->s_lsn.offset = lp->lsn.offset - 1; + } + + /* + * Save the last known offset from the previous file, we'll + * need it to initialize the persistent header information. + */ + lastoff = lp->lsn.offset; + + ++lp->lsn.file; + lp->lsn.offset = 0; + lp->w_off = 0; + } else + lastoff = 0; + + /* + * Insert persistent information as the first record in every file. + * Note that the previous length is wrong for the very first record + * of the log, but that's okay, we check for it during retrieval. + */ + if (lp->lsn.offset == 0) { + t.data = &lp->persist; + t.size = sizeof(LOGP); + if ((ret = __log_putr(dblp, + &t, lastoff == 0 ? 0 : lastoff - lp->len)) != 0) + return (ret); + } + + /* Initialize the LSN information returned to the user. */ + lsn->file = lp->lsn.file; + lsn->offset = lp->lsn.offset; + + /* Put out the user's record. */ + if ((ret = __log_putr(dblp, dbt, lp->lsn.offset - lp->len)) != 0) + return (ret); + + /* + * On a checkpoint, we: + * Put out the checkpoint record (above). + * Save the LSN of the checkpoint in the shared region. + * Append the set of file name information into the log. + * Flush the current buffer contents to disk. + * Sync the log to disk. + * Save the time the checkpoint was written. + * Reset the bytes written since the last checkpoint. + */ + if (flags == DB_CHECKPOINT) { + lp->c_lsn = *lsn; + + for (fnp = SH_TAILQ_FIRST(&dblp->lp->fq, __fname); + fnp != NULL; fnp = SH_TAILQ_NEXT(fnp, q, __fname)) { + t.data = ADDR(dblp, fnp->name_off); + t.size = strlen(t.data) + 1; + memset(&fid_dbt, 0, sizeof(fid_dbt)); + fid_dbt.data = ADDR(dblp, fnp->fileid_off); + fid_dbt.size = DB_FILE_ID_LEN; + if ((ret = __log_register_log(dblp, NULL, &r_unused, + 0, &t, &fid_dbt, fnp->id, fnp->s_type)) != 0) + return (ret); + } + if (lp->b_off != 0 && + (ret = __log_write(dblp, lp->buf, lp->b_off)) != 0) + return (ret); + (void)time(&lp->chkpt); + lp->written = 0; + + if ((ret = __db_fsync(dblp->lfd)) != 0) + return (ret); + lp->s_lsn.file = lp->lsn.file; + lp->s_lsn.offset = lp->lsn.offset - 1; + } + + /* We always flush on a checkpoint. */ + if (flags == DB_FLUSH || flags == DB_CHECKPOINT) { + if (lp->b_off != 0 && + (ret = __log_write(dblp, lp->buf, lp->b_off)) != 0) + return (ret); + + if ((ret = __db_fsync(dblp->lfd)) != 0) + return (ret); + lp->s_lsn.file = lp->lsn.file; + lp->s_lsn.offset = lp->lsn.offset - 1; + } + + /* + * If we just did I/O, i.e., this LSN could have spanned the start of + * the in-core buffer, we remember it so that we can flush correctly + * during a sync. + */ + if (lsn->offset < lp->w_off && lsn->offset + lp->len > lp->w_off) + lp->span_lsn = *lsn; + return (0); +} + +/* + * __log_putr -- + * Actually put a record into the log. + */ +static int +__log_putr(dblp, dbt, prev) + DB_LOG *dblp; + const DBT *dbt; + u_int32_t prev; +{ + HDR hdr; + LOG *lp; + int ret; + + lp = dblp->lp; + + /* + * Initialize the header. If we just switched files, lsn.offset will + * be 0, and what we really want is the offset of the previous record + * in the previous file. Fortunately, prev holds the value we want. + */ + hdr.prev = prev; + hdr.len = sizeof(HDR) + dbt->size; + hdr.cksum = __ham_func4(dbt->data, dbt->size); + + if ((ret = __log_fill(dblp, &hdr, sizeof(HDR))) != 0) + return (ret); + lp->lsn.offset += sizeof(HDR); + + if ((ret = __log_fill(dblp, dbt->data, dbt->size)) != 0) + return (ret); + lp->lsn.offset += dbt->size; + + lp->len = sizeof(HDR) + dbt->size; + return (0); +} + +/* + * log_flush -- + * Write all records less than or equal to the specified LSN. + */ +int +log_flush(dblp, lsn) + DB_LOG *dblp; + const DB_LSN *lsn; +{ + DB_LSN t_lsn; + LOG *lp; + int ret; + + ret = 0; + lp = dblp->lp; + + LOCK_LOGREGION(dblp); + + /* If no LSN specified, flush the entire log. */ + if (lsn == NULL) { + t_lsn.file = lp->lsn.file; + t_lsn.offset = lp->lsn.offset - lp->len; + lsn = &t_lsn; + } + + /* If it's a non-existent record, it's an error. */ + if (lsn->file > lp->lsn.file || + (lsn->file == lp->lsn.file && lsn->offset > lp->lsn.offset)) { + __db_err(dblp->dbenv, "log_flush: LSN past current end-of-log"); + ret = EINVAL; + goto ret1; + } + + /* + * If it's from a previous file, we're done because we sync each + * file when we move to a new one. + */ + if (lsn->file < lp->lsn.file) + goto ret1; + + /* + * If it's less than the last-sync'd offset, we've already sync'd + * this LSN. + */ + if (lsn->offset <= lp->s_lsn.offset) + goto ret1; + + /* + * We may need to write the current buffer. We have to write the + * current buffer if the sync LSN is greater than or equal to the + * saved spanning-LSN. + */ + if (lsn->file >= lp->span_lsn.file && + lsn->offset >= lp->span_lsn.offset) + if ((ret = __log_write(dblp, lp->buf, lp->b_off)) != 0) + goto ret1; + + /* Acquire a file descriptor if we don't have one. */ + if (dblp->lfname != dblp->lp->lsn.file && + (ret = __log_newfd(dblp)) != 0) + goto ret1; + + if ((ret = __db_fsync(dblp->lfd)) != 0) + goto ret1; + + lp->s_lsn.file = lp->lsn.file; + lp->s_lsn.offset = lsn->offset; + +ret1: UNLOCK_LOGREGION(dblp); + return (ret); +} + +/* + * __log_fill -- + * Write information into the log. + */ +static int +__log_fill(dblp, addr, len) + DB_LOG *dblp; + void *addr; + u_int32_t len; +{ + LOG *lp; + u_int32_t nrec; + size_t nw, remain; + int ret; + + /* Copy out the data. */ + for (lp = dblp->lp; len > 0;) { + /* + * If we're on a buffer boundary and the data is big enough, + * copy as many records as we can directly from the data. + */ + if (lp->b_off == 0 && len >= sizeof(lp->buf)) { + nrec = len / sizeof(lp->buf); + if ((ret = __log_write(dblp, + addr, nrec * sizeof(lp->buf))) != 0) + return (ret); + addr = (u_int8_t *)addr + nrec * sizeof(lp->buf); + len -= nrec * sizeof(lp->buf); + continue; + } + + /* Figure out how many bytes we can copy this time. */ + remain = sizeof(lp->buf) - lp->b_off; + nw = remain > len ? len : remain; + memcpy(lp->buf + lp->b_off, addr, nw); + addr = (u_int8_t *)addr + nw; + len -= nw; + lp->b_off += nw; + + /* If we fill the buffer, flush it. */ + if (lp->b_off == sizeof(lp->buf) && + (ret = __log_write(dblp, lp->buf, sizeof(lp->buf))) != 0) + return (ret); + } + return (0); +} + +/* + * __log_write -- + * Write the log buffer to disk. + */ +static int +__log_write(dblp, addr, len) + DB_LOG *dblp; + void *addr; + u_int32_t len; +{ + LOG *lp; + ssize_t nw; + int ret; + + /* + * If we haven't opened the log file yet or the current one + * has changed, acquire a new log file. + */ + lp = dblp->lp; + if (dblp->lfd == -1 || dblp->lfname != lp->lsn.file) + if ((ret = __log_newfd(dblp)) != 0) + return (ret); + + /* + * Seek to the offset in the file (someone may have written it + * since we last did). + */ + if ((ret = __db_lseek(dblp->lfd, 0, 0, lp->w_off, SEEK_SET)) != 0) + return (ret); + if ((ret = __db_write(dblp->lfd, addr, len, &nw)) != 0) + return (ret); + if (nw != (int32_t)len) + return (EIO); + + /* Update the seek offset and reset the buffer offset. */ + lp->b_off = 0; + lp->w_off += len; + lp->written += len; + + return (0); +} + +/* + * log_file -- + * Map a DB_LSN to a file name. + */ +int +log_file(dblp, lsn, namep, len) + DB_LOG *dblp; + const DB_LSN *lsn; + char *namep; + size_t len; +{ + int ret; + char *p; + + LOCK_LOGREGION(dblp); + + ret = __log_name(dblp->dbenv, lsn->file, &p); + + UNLOCK_LOGREGION(dblp); + + if (ret != 0) + return (ret); + + /* Check to make sure there's enough room and copy the name. */ + if (len < strlen(p)) { + *namep = '\0'; + return (ENOMEM); + } + (void)strcpy(namep, p); + free(p); + + return (0); +} + +/* + * __log_newfd -- + * Acquire a file descriptor for the current log file. + */ +static int +__log_newfd(dblp) + DB_LOG *dblp; +{ + int ret; + char *p; + + /* Close any previous file descriptor. */ + if (dblp->lfd != -1) { + (void)__db_close(dblp->lfd); + dblp->lfd = -1; + } + + /* Get the path of the new file and open it. */ + dblp->lfname = dblp->lp->lsn.file; + if ((ret = __log_name(dblp->dbenv, dblp->lfname, &p)) != 0) + return (ret); + if ((ret = __db_fdopen(p, + DB_CREATE | DB_SEQUENTIAL, + DB_CREATE | DB_SEQUENTIAL, + dblp->lp->persist.mode, &dblp->lfd)) != 0) + __db_err(dblp->dbenv, + "log_put: %s: %s", p, strerror(errno)); + FREES(p); + return (ret); +} + +/* + * __log_name -- + * Return the log name for a particular file. + * + * PUBLIC: int __log_name __P((DB_ENV *, int, char **)); + */ +int +__log_name(dbenv, fn, np) + DB_ENV *dbenv; + int fn; + char **np; +{ + char name[sizeof(LFNAME) + 10]; + + (void)snprintf(name, sizeof(name), LFNAME, fn); + return (__db_appname(dbenv, DB_APP_LOG, NULL, name, NULL, np)); +} |