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Diffstat (limited to 'src/knot/journal/journal_read.h')
| -rw-r--r-- | src/knot/journal/journal_read.h | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/knot/journal/journal_read.h b/src/knot/journal/journal_read.h new file mode 100644 index 0000000..92cad9f --- /dev/null +++ b/src/knot/journal/journal_read.h @@ -0,0 +1,158 @@ +/* Copyright (C) 2019 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#pragma once + +#include "knot/journal/journal_basic.h" + +typedef struct journal_read journal_read_t; + +typedef int (*journal_read_cb_t)(bool in_remove_section, const knot_rrset_t *rr, void *ctx); + +typedef int (*journal_walk_cb_t)(bool special, const changeset_t *ch, void *ctx); + +/*! + * \brief Start reading journal from specified changeset. + * + * \param j Journal to be read. + * \param read_zone True if reading shall start with zone-in-journal. + * \param serial_from Serial-from of the changeset to be started at (ignored if 'read_zone'). + * \param ctx Output: journal reading context initialised. + * + * \return KNOT_E* + */ +int journal_read_begin(zone_journal_t j, bool read_zone, uint32_t serial_from, journal_read_t **ctx); + +/*! + * \brief Read a single RRSet from a journal changeset. + * + * \param ctx Journal reading context. + * \param rr Output: RRSet to be filled with serialized data. + * \param allow_next_changeset True to allow jumping to next changeset. + * + * \return False if no more RRSet in this changeset/journal, or failure. + */ +bool journal_read_rrset(journal_read_t *ctx, knot_rrset_t *rr, bool allow_next_changeset); + +/*! + * \brief Free up heap allocations by journal_read_rrset(). + * + * \param rr RRSet initialised by journal_read_rrset(). + */ +void journal_read_clear_rrset(knot_rrset_t *rr); + +// TODO move somewhere. Libknot? +inline static bool rr_is_apex_soa(const knot_rrset_t *rr, const knot_dname_t *apex) +{ + return (rr->type == KNOT_RRTYPE_SOA && knot_dname_is_equal(rr->owner, apex)); +} + +/*! + * \brief Read all RRSets up to the end of journal, calling a function for each. + * + * \note Closes reading context at the end. + * + * \param read Journal reading context. + * \param cb Callback to be called on each read. + * \param ctx Arbitrary context to be passed to the callback. + * + * \return An error code from either journal operations or from the callback. + */ +int journal_read_rrsets(journal_read_t *read, journal_read_cb_t cb, void *ctx); + +/*! + * \brief Read a single changeset from journal. + * + * \param ctx Journal reading context. + * \param ch Output: changeset to be filled with serialized data. + * + * \return False if no more changesets in the journal, or failure. + */ +bool journal_read_changeset(journal_read_t *ctx, changeset_t *ch); + +/*! + * \brief Free up heap allocations by journal_read_changeset(). + * + * \param ch Changeset initialised by journal_read_changeset(). + */ +void journal_read_clear_changeset(changeset_t *ch); + +/*! + * \brief Obtain error code from the journal_read operations previously performed. + * + * \param ctx Journal reading context. + * \param another_error An error code from outside the reading operations to be combined. + * + * \return KNOT_EOK if completely every operation succeeded, KNOT_E* + */ +int journal_read_get_error(const journal_read_t *ctx, int another_error); + +/*! + * \brief Finalise journal reading. + * + * \param ctx Journal reading context (will be freed). + */ +void journal_read_end(journal_read_t *ctx); + +/*! + * \brief Call a function for each changeset in journal. + * + * This is a variant of journal_walk() see below. + * The difference is that iteration starts at specified serial. + * Similarly to how IXFR works. + * The callback is called for each found changeset, or just once + * with ch=NULL if none is found. + * + * \param j Zone journal to be read. + * \param from SOA serial to start at. + * \param cb Callback to be called for each changeset (or its non-existence). + * \param ctx Arbitrary context to be passed to the callback. + * + * \return An error code from either journal operations or from the callback. + * \retval KNOT_ENOENT if the journal is not empty, but the requested serial not present. + */ +int journal_walk_from(zone_journal_t j, uint32_t from, + journal_walk_cb_t cb, void *ctx); + +/*! + * \brief Call a function for each changeset stored in journal. + * + * First, the callback will be called for the special changeset - + * either zone-in-journal or merged changeset, with special=true. + * If there is no such, it will be called anyway with ch=NULL. + * + * Than, the callback will be called for each regular changeset + * with special=false. If there is none, it will be called once + * with ch=NULL. + * + * \param j Zone journal to be read. + * \param cb Callback to be called for each changeset (or its non-existence). + * \param ctx Arbitrary context to be passed to the callback. + * + * \return An error code from either journal operations or from the callback. + */ +int journal_walk(zone_journal_t j, journal_walk_cb_t cb, void *ctx); + +/*! + * \brief Perform semantic check of the zone journal (consistency, metadata...). + * + * \param j Zone journal to be checked. + * + * \retval KNOT_E* ( < 0 ) if an error during journal operation. + * \retval > 100 if some inconsistency found. + * \return KNOT_EOK of all ok. + */ +int journal_sem_check(zone_journal_t j); |