From 89612ec05f596d135640413e093251fb9691ca14 Mon Sep 17 00:00:00 2001 From: David Robillard Date: Sun, 30 May 2021 12:23:07 -0400 Subject: Add support for converting literals to canonical form --- src/canon.c | 192 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 192 insertions(+) create mode 100644 src/canon.c (limited to 'src/canon.c') diff --git a/src/canon.c b/src/canon.c new file mode 100644 index 00000000..84d20d0c --- /dev/null +++ b/src/canon.c @@ -0,0 +1,192 @@ +/* + Copyright 2019-2022 David Robillard + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#include "caret.h" +#include "namespaces.h" +#include "node.h" +#include "statement.h" +#include "string_utils.h" + +#include "exess/exess.h" +#include "serd/serd.h" + +#include +#include +#include + +typedef struct { + const SerdWorld* world; + const SerdSink* target; + SerdCanonFlags flags; +} SerdCanonData; + +static ExessResult +build_typed(SerdNode** const out, + const SerdNode* const SERD_NONNULL node, + const SerdNode* const SERD_NONNULL datatype) +{ + *out = NULL; + + const char* str = serd_node_string(node); + const char* datatype_uri = serd_node_string(datatype); + ExessResult r = {EXESS_SUCCESS, 0}; + + if (!strcmp(datatype_uri, NS_RDF "langString")) { + *out = serd_new_string(serd_node_string_view(node)); + return r; + } + + const ExessDatatype value_type = exess_datatype_from_uri(datatype_uri); + if (value_type == EXESS_NOTHING) { + return r; + } + + // Measure canonical form to know how much space to allocate for node + if ((r = exess_write_canonical(str, value_type, 0, NULL)).status) { + return r; + } + + // Allocate node + const size_t datatype_uri_len = serd_node_length(datatype); + const size_t datatype_size = serd_node_total_size(datatype); + const size_t len = serd_node_pad_length(r.count); + const size_t total_len = sizeof(SerdNode) + len + datatype_size; + SerdNode* const result = serd_node_malloc(total_len); + + result->length = r.count; + result->flags = SERD_HAS_DATATYPE; + result->type = SERD_LITERAL; + + // Write canonical form directly into node + exess_write_canonical(str, value_type, r.count + 1, serd_node_buffer(result)); + + SerdNode* const datatype_node = result + 1 + (len / sizeof(SerdNode)); + char* const datatype_buf = serd_node_buffer(datatype_node); + + datatype_node->length = datatype_uri_len; + datatype_node->type = SERD_URI; + memcpy(datatype_buf, datatype_uri, datatype_uri_len + 1); + + *out = result; + return r; +} + +static ExessResult +build_tagged(SerdNode** const out, + const SerdNode* const SERD_NONNULL node, + const SerdNode* const SERD_NONNULL language) +{ +#define MAX_LANG_LEN 48 // RFC5646 requires 35, RFC4646 recommends 42 + + const size_t node_len = serd_node_length(node); + const char* const lang = serd_node_string(language); + const size_t lang_len = serd_node_length(language); + if (lang_len > MAX_LANG_LEN) { + const ExessResult r = {EXESS_NO_SPACE, node_len}; + return r; + } + + // Convert language tag to lower-case + char canonical_lang[MAX_LANG_LEN] = {0}; + for (size_t i = 0u; i < lang_len; ++i) { + canonical_lang[i] = serd_to_lower(lang[i]); + } + + // Make a new literal that is otherwise identical + *out = serd_new_literal(serd_node_string_view(node), + serd_node_flags(node), + SERD_SUBSTRING(canonical_lang, lang_len)); + + const ExessResult r = {EXESS_SUCCESS, node_len}; + return r; + +#undef MAX_LANG_LEN +} + +static SerdStatus +serd_canon_on_statement(SerdCanonData* const data, + const SerdStatementFlags flags, + const SerdStatement* const statement) +{ + const SerdNode* const object = serd_statement_object(statement); + const SerdNode* const datatype = serd_node_datatype(object); + const SerdNode* const language = serd_node_language(object); + if (!datatype && !language) { + return serd_sink_write_statement(data->target, flags, statement); + } + + SerdNode* normo = NULL; + const ExessResult r = datatype ? build_typed(&normo, object, datatype) + : build_tagged(&normo, object, language); + + if (r.status) { + SerdCaret caret = {NULL, 0u, 0u}; + const bool lax = (data->flags & SERD_CANON_LAX); + + if (statement->caret) { + // Adjust column to point at the error within the literal + caret.file = statement->caret->file; + caret.line = statement->caret->line; + caret.col = statement->caret->col + 1 + (unsigned)r.count; + } + + serd_logf_at(data->world, + lax ? SERD_LOG_LEVEL_WARNING : SERD_LOG_LEVEL_ERROR, + statement->caret ? &caret : NULL, + "invalid literal (%s)", + exess_strerror(r.status)); + + if (!lax) { + return SERD_ERR_INVALID; + } + } + + if (!normo) { + return serd_sink_write_statement(data->target, flags, statement); + } + + const SerdStatus st = serd_sink_write(data->target, + flags, + statement->nodes[0], + statement->nodes[1], + normo, + statement->nodes[3]); + serd_node_free(normo); + return st; +} + +static SerdStatus +serd_canon_on_event(SerdCanonData* const data, const SerdEvent* const event) +{ + return (event->type == SERD_STATEMENT) + ? serd_canon_on_statement( + data, event->statement.flags, event->statement.statement) + : serd_sink_write_event(data->target, event); +} + +SerdSink* +serd_canon_new(const SerdWorld* const world, + const SerdSink* const target, + const SerdCanonFlags flags) +{ + SerdCanonData* const data = (SerdCanonData*)calloc(1, sizeof(SerdCanonData)); + + data->world = world; + data->target = target; + data->flags = flags; + + return serd_sink_new(data, (SerdEventFunc)serd_canon_on_event, free); +} -- cgit v1.2.1