// Copyright 2011-2023 David Robillard // SPDX-License-Identifier: ISC #include "attributes.h" #include "byte_sink.h" #include "serd_internal.h" #include "stack.h" #include "string_utils.h" #include "try.h" #include "uri_utils.h" #include "serd/serd.h" #include #include #include #include #include #include #include typedef enum { CTX_NAMED, ///< Normal non-anonymous context CTX_BLANK, ///< Anonymous blank node CTX_LIST, ///< Anonymous list } ContextType; typedef enum { FIELD_NONE, FIELD_SUBJECT, FIELD_PREDICATE, FIELD_OBJECT, FIELD_GRAPH, } Field; typedef struct { ContextType type; SerdNode graph; SerdNode subject; SerdNode predicate; bool predicates; bool comma_indented; } WriteContext; static const WriteContext WRITE_CONTEXT_NULL = {CTX_NAMED, {0, 0, 0, SERD_NOTHING}, {0, 0, 0, SERD_NOTHING}, {0, 0, 0, SERD_NOTHING}, 0U, 0U}; typedef enum { SEP_NONE, ///< Sentinel before the start of a document SEP_NODE, ///< Sentinel after a node SEP_NEWLINE, ///< Sentinel after a node SEP_END_DIRECT, ///< End of a directive (like "@prefix") SEP_END_S, ///< End of a subject ('.') SEP_END_P, ///< End of a predicate (';') SEP_END_O, ///< End of a named object (',') SEP_JOIN_O_AN, ///< End of anonymous object (',') before a named one SEP_JOIN_O_NA, ///< End of named object (',') before an anonymous one SEP_JOIN_O_AA, ///< End of anonymous object (',') before another SEP_S_P, ///< Between a subject and predicate (whitespace) SEP_P_O, ///< Between a predicate and object (whitespace) SEP_ANON_BEGIN, ///< Start of anonymous node ('[') SEP_ANON_S_P, ///< Between anonymous subject and predicate (whitespace) SEP_ANON_END, ///< End of anonymous node (']') SEP_LIST_BEGIN, ///< Start of list ('(') SEP_LIST_SEP, ///< List separator (whitespace) SEP_LIST_END, ///< End of list (')') SEP_GRAPH_BEGIN, ///< Start of graph ('{') SEP_GRAPH_END, ///< End of graph ('}') } Sep; typedef uint32_t SepMask; ///< Bitfield of separator flags typedef struct { char sep; ///< Sep character int indent; ///< Indent delta SepMask pre_space_after; ///< Leading space if after given seps SepMask pre_line_after; ///< Leading newline if after given seps SepMask post_line_after; ///< Trailing newline if after given seps } SepRule; #define SEP_EACH (~(SepMask)0) #define M(s) (1U << (s)) #define NIL '\0' static const SepRule rules[] = { {NIL, +0, SEP_NONE, SEP_NONE, SEP_NONE}, {NIL, +0, SEP_NONE, SEP_NONE, SEP_NONE}, {'\n', 0, SEP_NONE, SEP_NONE, SEP_NONE}, {'.', +0, SEP_EACH, SEP_NONE, SEP_EACH}, {'.', +0, SEP_EACH, SEP_NONE, SEP_NONE}, {';', +0, SEP_EACH, SEP_NONE, SEP_EACH}, {',', +0, SEP_EACH, SEP_NONE, SEP_EACH}, {',', +0, SEP_EACH, SEP_NONE, SEP_EACH}, {',', +0, SEP_EACH, SEP_NONE, SEP_EACH}, {',', +0, SEP_EACH, SEP_NONE, SEP_NONE}, {NIL, +1, SEP_NONE, SEP_NONE, SEP_EACH}, {' ', +0, SEP_NONE, SEP_NONE, SEP_NONE}, {'[', +1, M(SEP_JOIN_O_AA), SEP_NONE, SEP_NONE}, {NIL, +1, SEP_NONE, SEP_NONE, M(SEP_ANON_BEGIN)}, {']', -1, SEP_NONE, ~M(SEP_ANON_BEGIN), SEP_NONE}, {'(', +1, M(SEP_JOIN_O_AA), SEP_NONE, SEP_EACH}, {NIL, +0, SEP_NONE, SEP_EACH, SEP_NONE}, {')', -1, SEP_NONE, SEP_EACH, SEP_NONE}, {'{', +1, SEP_EACH, SEP_NONE, SEP_EACH}, {'}', -1, SEP_NONE, SEP_NONE, SEP_EACH}, }; #undef NIL #undef M #undef SEP_EACH struct SerdWriterImpl { SerdSyntax syntax; SerdStyle style; SerdEnv* env; SerdNode root_node; SerdURI root_uri; SerdURI base_uri; SerdStack anon_stack; SerdByteSink byte_sink; SerdErrorSink error_sink; void* error_handle; WriteContext context; uint8_t* bprefix; size_t bprefix_len; Sep last_sep; int indent; }; typedef enum { WRITE_STRING, WRITE_LONG_STRING } TextContext; typedef enum { RESET_GRAPH = 1U << 0U, RESET_INDENT = 1U << 1U } ResetFlag; SERD_NODISCARD static SerdStatus write_node(SerdWriter* writer, const SerdNode* node, const SerdNode* datatype, const SerdNode* lang, Field field, SerdStatementFlags flags); SERD_NODISCARD static bool supports_abbrev(const SerdWriter* writer) { return writer->syntax == SERD_TURTLE || writer->syntax == SERD_TRIG; } SERD_NODISCARD static bool supports_uriref(const SerdWriter* writer) { return writer->syntax == SERD_TURTLE || writer->syntax == SERD_TRIG; } static SerdStatus free_context(WriteContext* const ctx) { serd_node_free(&ctx->graph); serd_node_free(&ctx->subject); serd_node_free(&ctx->predicate); ctx->graph.type = SERD_NOTHING; ctx->subject.type = SERD_NOTHING; ctx->predicate.type = SERD_NOTHING; return SERD_SUCCESS; } SERD_LOG_FUNC(3, 4) static SerdStatus w_err(SerdWriter* writer, SerdStatus st, const char* fmt, ...) { /* TODO: This results in errors with no file information, which is not helpful when re-serializing a file (particularly for "undefined namespace prefix" errors. The statement sink API needs to be changed to add a Cursor parameter so the source can notify the writer of the statement origin for better error reporting. */ va_list args; // NOLINT(cppcoreguidelines-init-variables) va_start(args, fmt); const SerdError e = {st, (const uint8_t*)"", 0, 0, fmt, &args}; serd_error(writer->error_sink, writer->error_handle, &e); va_end(args); return st; } static void copy_node(SerdNode* dst, const SerdNode* src) { const size_t new_size = src->n_bytes + 1U; uint8_t* const new_buf = (uint8_t*)realloc((char*)dst->buf, new_size); if (new_buf) { dst->buf = new_buf; dst->n_bytes = src->n_bytes; dst->flags = src->flags; dst->type = src->type; memcpy((char*)dst->buf, src->buf, new_size); } } static void push_context(SerdWriter* const writer, const ContextType type, const SerdNode graph, const SerdNode subject, const SerdNode predicate) { // Push the current context to the stack void* const top = serd_stack_push(&writer->anon_stack, sizeof(WriteContext)); *(WriteContext*)top = writer->context; // Update the current context const WriteContext current = {type, graph, subject, predicate, 0U, 0U}; writer->context = current; } static void pop_context(SerdWriter* writer) { // Replace the current context with the top of the stack free_context(&writer->context); writer->context = *(WriteContext*)(writer->anon_stack.buf + writer->anon_stack.size - sizeof(WriteContext)); // Pop the top of the stack away serd_stack_pop(&writer->anon_stack, sizeof(WriteContext)); } SERD_NODISCARD static size_t sink(const void* buf, size_t len, SerdWriter* writer) { const size_t written = serd_byte_sink_write(buf, len, &writer->byte_sink); if (written != len) { if (errno) { const char* const message = strerror(errno); w_err(writer, SERD_ERR_BAD_WRITE, "write error (%s)\n", message); } else { w_err(writer, SERD_ERR_BAD_WRITE, "write error\n"); } } return written; } SERD_NODISCARD static inline SerdStatus esink(const void* buf, size_t len, SerdWriter* writer) { return sink(buf, len, writer) == len ? SERD_SUCCESS : SERD_ERR_BAD_WRITE; } // Write a single character, as an escape for single byte characters // (Caller prints any single byte characters that don't need escaping) static size_t write_character(SerdWriter* writer, const uint8_t* utf8, size_t* size, SerdStatus* st) { char escape[11] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; const uint32_t c = parse_utf8_char(utf8, size); switch (*size) { case 0: *st = w_err(writer, SERD_ERR_BAD_TEXT, "invalid UTF-8 start: %X\n", utf8[0]); return 0; case 1: snprintf(escape, sizeof(escape), "\\u%04X", utf8[0]); return sink(escape, 6, writer); default: break; } if (!(writer->style & SERD_STYLE_ASCII)) { // Write UTF-8 character directly to UTF-8 output return sink(utf8, *size, writer); } if (c <= 0xFFFF) { snprintf(escape, sizeof(escape), "\\u%04X", c); return sink(escape, 6, writer); } snprintf(escape, sizeof(escape), "\\U%08X", c); return sink(escape, 10, writer); } SERD_NODISCARD static bool uri_must_escape(const uint8_t c) { switch (c) { case ' ': case '"': case '<': case '>': case '\\': case '^': case '`': case '{': case '|': case '}': return true; default: return !in_range(c, 0x20, 0x7E); } } static size_t write_uri(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes, SerdStatus* st) { size_t len = 0; for (size_t i = 0; i < n_bytes;) { size_t j = i; // Index of next character that must be escaped for (; j < n_bytes; ++j) { if (uri_must_escape(utf8[j])) { break; } } // Bulk write all characters up to this special one const size_t n_bulk = sink(&utf8[i], j - i, writer); len += n_bulk; if (n_bulk != j - i) { *st = SERD_ERR_BAD_WRITE; return len; } if ((i = j) == n_bytes) { break; // Reached end } // Write UTF-8 character size_t size = 0; len += write_character(writer, utf8 + i, &size, st); i += size; if (*st && (writer->style & SERD_STYLE_STRICT)) { break; } if (size == 0) { // Corrupt input, write percent-encoded bytes and scan to next start char escape[4] = {0, 0, 0, 0}; for (; i < n_bytes && (utf8[i] & 0x80); ++i) { snprintf(escape, sizeof(escape), "%%%02X", utf8[i]); len += sink(escape, 3, writer); } } } return len; } SERD_NODISCARD static SerdStatus ewrite_uri(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes) { SerdStatus st = SERD_SUCCESS; write_uri(writer, utf8, n_bytes, &st); return (st == SERD_ERR_BAD_WRITE || (writer->style & SERD_STYLE_STRICT)) ? st : SERD_SUCCESS; } SERD_NODISCARD static SerdStatus write_uri_from_node(SerdWriter* writer, const SerdNode* node) { return ewrite_uri(writer, node->buf, node->n_bytes); } static bool lname_must_escape(const uint8_t c) { /* This arbitrary list of characters, most of which have nothing to do with Turtle, must be handled as special cases here because the RDF and SPARQL WGs are apparently intent on making the once elegant Turtle a baroque and inconsistent mess, throwing elegance and extensibility completely out the window for no good reason. Note '-', '.', and '_' are also in PN_LOCAL_ESC, but are valid unescaped in local names, so they are not escaped here. */ switch (c) { case '\'': case '!': case '#': case '$': case '%': case '&': case '(': case ')': case '*': case '+': case ',': case '/': case ';': case '=': case '?': case '@': case '~': return true; default: break; } return false; } SERD_NODISCARD static SerdStatus write_lname(SerdWriter* writer, const uint8_t* utf8, size_t n_bytes) { SerdStatus st = SERD_SUCCESS; for (size_t i = 0; i < n_bytes; ++i) { size_t j = i; // Index of next character that must be escaped for (; j < n_bytes; ++j) { if (lname_must_escape(utf8[j])) { break; } } // Bulk write all characters up to this special one TRY(st, esink(&utf8[i], j - i, writer)); if ((i = j) == n_bytes) { break; // Reached end } // Write escape TRY(st, esink("\\", 1, writer)); TRY(st, esink(&utf8[i], 1, writer)); } return st; } SERD_NODISCARD static SerdStatus write_text(SerdWriter* writer, TextContext ctx, const uint8_t* utf8, size_t n_bytes) { size_t n_consecutive_quotes = 0; SerdStatus st = SERD_SUCCESS; for (size_t i = 0; !st && i < n_bytes;) { if (utf8[i] != '"') { n_consecutive_quotes = 0; } // Fast bulk write for long strings of printable ASCII size_t j = i; for (; j < n_bytes; ++j) { if (utf8[j] == '\\' || utf8[j] == '"' || (!in_range(utf8[j], 0x20, 0x7E))) { break; } } st = esink(&utf8[i], j - i, writer); if ((i = j) == n_bytes) { break; // Reached end } const uint8_t in = utf8[i++]; if (ctx == WRITE_LONG_STRING) { n_consecutive_quotes = (in == '\"') ? (n_consecutive_quotes + 1) : 0; switch (in) { case '\\': st = esink("\\\\", 2, writer); continue; case '\b': st = esink("\\b", 2, writer); continue; case '\n': case '\r': case '\t': case '\f': st = esink(&in, 1, writer); // Write character as-is continue; case '\"': if (n_consecutive_quotes >= 3 || i == n_bytes) { // Two quotes in a row, or quote at string end, escape st = esink("\\\"", 2, writer); } else { st = esink(&in, 1, writer); } continue; default: break; } } else { switch (in) { case '\\': st = esink("\\\\", 2, writer); continue; case '\n': st = esink("\\n", 2, writer); continue; case '\r': st = esink("\\r", 2, writer); continue; case '\t': st = esink("\\t", 2, writer); continue; case '"': st = esink("\\\"", 2, writer); continue; default: break; } if (writer->syntax == SERD_TURTLE) { switch (in) { case '\b': st = esink("\\b", 2, writer); continue; case '\f': st = esink("\\f", 2, writer); continue; default: break; } } } // Write UTF-8 character size_t size = 0; write_character(writer, utf8 + i - 1, &size, &st); if (st && (writer->style & SERD_STYLE_STRICT)) { return st; } if (size == 0) { // Corrupt input, write replacement character and scan to the next start st = esink(replacement_char, sizeof(replacement_char), writer); for (; i < n_bytes && (utf8[i] & 0x80); ++i) { } } else { i += size - 1; } } return (writer->style & SERD_STYLE_STRICT) ? st : SERD_SUCCESS; } typedef struct { SerdWriter* writer; SerdStatus status; } UriSinkContext; SERD_NODISCARD static size_t uri_sink(const void* buf, size_t len, void* stream) { UriSinkContext* const context = (UriSinkContext*)stream; SerdWriter* const writer = context->writer; return write_uri(writer, (const uint8_t*)buf, len, &context->status); } SERD_NODISCARD static SerdStatus write_newline(SerdWriter* writer) { SerdStatus st = SERD_SUCCESS; TRY(st, esink("\n", 1, writer)); for (int i = 0; i < writer->indent; ++i) { TRY(st, esink("\t", 1, writer)); } return st; } SERD_NODISCARD static SerdStatus write_sep(SerdWriter* writer, const Sep sep) { SerdStatus st = SERD_SUCCESS; const SepRule* const rule = &rules[sep]; const bool pre_line = (rule->pre_line_after & (1U << writer->last_sep)); const bool post_line = (rule->post_line_after & (1U << writer->last_sep)); // Adjust indent, but tolerate if it would become negative if (rule->indent && (pre_line || post_line)) { writer->indent = ((rule->indent >= 0 || writer->indent >= -rule->indent) ? writer->indent + rule->indent : 0); } // If this is the first comma, bump the increment for the following object if (sep == SEP_END_O && !writer->context.comma_indented) { ++writer->indent; writer->context.comma_indented = true; } // Write newline or space before separator if necessary if (pre_line) { TRY(st, write_newline(writer)); } else if (rule->pre_space_after & (1U << writer->last_sep)) { TRY(st, esink(" ", 1, writer)); } // Write actual separator string if (rule->sep) { TRY(st, esink(&rule->sep, 1, writer)); } // Write newline after separator if necessary if (post_line) { TRY(st, write_newline(writer)); if (rule->post_line_after != ~(SepMask)0U) { writer->last_sep = SEP_NEWLINE; } } // Reset context and write a blank line after ends of subjects if (sep == SEP_END_S) { writer->indent = writer->context.graph.type ? 1 : 0; writer->context.predicates = false; writer->context.comma_indented = false; TRY(st, esink("\n", 1, writer)); } writer->last_sep = sep; return st; } static void free_anon_stack(SerdWriter* writer) { while (!serd_stack_is_empty(&writer->anon_stack)) { pop_context(writer); } } static SerdStatus reset_context(SerdWriter* writer, const unsigned flags) { free_anon_stack(writer); if (flags & RESET_GRAPH) { writer->context.graph.type = SERD_NOTHING; } if (flags & RESET_INDENT) { writer->indent = 0; } writer->context.type = CTX_NAMED; writer->context.subject.type = SERD_NOTHING; writer->context.predicate.type = SERD_NOTHING; writer->context.predicates = false; writer->context.comma_indented = false; return SERD_SUCCESS; } SERD_NODISCARD static SerdStatus write_literal(SerdWriter* writer, const SerdNode* node, const SerdNode* datatype, const SerdNode* lang, SerdStatementFlags flags) { SerdStatus st = SERD_SUCCESS; if (supports_abbrev(writer) && datatype && datatype->buf) { const char* type_uri = (const char*)datatype->buf; if (!strncmp(type_uri, NS_XSD, sizeof(NS_XSD) - 1) && (!strcmp(type_uri + sizeof(NS_XSD) - 1, "boolean") || !strcmp(type_uri + sizeof(NS_XSD) - 1, "integer"))) { return esink(node->buf, node->n_bytes, writer); } if (!strncmp(type_uri, NS_XSD, sizeof(NS_XSD) - 1) && !strcmp(type_uri + sizeof(NS_XSD) - 1, "decimal") && strchr((const char*)node->buf, '.') && node->buf[node->n_bytes - 1] != '.') { /* xsd:decimal literals without trailing digits, e.g. "5.", can not be written bare in Turtle. We could add a 0 which is prettier, but changes the text and breaks round tripping. */ return esink(node->buf, node->n_bytes, writer); } } if (supports_abbrev(writer) && (node->flags & (SERD_HAS_NEWLINE | SERD_HAS_QUOTE))) { TRY(st, esink("\"\"\"", 3, writer)); TRY(st, write_text(writer, WRITE_LONG_STRING, node->buf, node->n_bytes)); TRY(st, esink("\"\"\"", 3, writer)); } else { TRY(st, esink("\"", 1, writer)); TRY(st, write_text(writer, WRITE_STRING, node->buf, node->n_bytes)); TRY(st, esink("\"", 1, writer)); } if (lang && lang->buf) { TRY(st, esink("@", 1, writer)); TRY(st, esink(lang->buf, lang->n_bytes, writer)); } else if (datatype && datatype->buf) { TRY(st, esink("^^", 2, writer)); return write_node(writer, datatype, NULL, NULL, FIELD_NONE, flags); } return st; } // Return true iff `buf` is a valid prefixed name prefix or suffix static bool is_name(const uint8_t* buf, const size_t len) { // TODO: This is more strict than it should be for (size_t i = 0; i < len; ++i) { if (!(is_alpha(buf[i]) || is_digit(buf[i]))) { return false; } } return true; } SERD_NODISCARD static SerdStatus write_uri_node(SerdWriter* const writer, const SerdNode* node, const Field field) { SerdStatus st = SERD_SUCCESS; SerdNode prefix = SERD_NODE_NULL; SerdChunk suffix = {NULL, 0U}; const bool has_scheme = serd_uri_string_has_scheme(node->buf); if (supports_abbrev(writer)) { if (field == FIELD_PREDICATE && !strcmp((const char*)node->buf, NS_RDF "type")) { return esink("a", 1, writer); } if (!strcmp((const char*)node->buf, NS_RDF "nil")) { return esink("()", 2, writer); } if (has_scheme && (writer->style & SERD_STYLE_CURIED) && serd_env_qualify(writer->env, node, &prefix, &suffix) && is_name(prefix.buf, prefix.n_bytes) && is_name(suffix.buf, suffix.len)) { TRY(st, write_uri_from_node(writer, &prefix)); TRY(st, esink(":", 1, writer)); return ewrite_uri(writer, suffix.buf, suffix.len); } } if (!has_scheme && !supports_uriref(writer) && !serd_env_get_base_uri(writer->env, NULL)->buf) { return w_err(writer, SERD_ERR_BAD_ARG, "syntax does not support URI reference <%s>\n", node->buf); } TRY(st, esink("<", 1, writer)); if (writer->style & SERD_STYLE_RESOLVED) { SerdURI in_base_uri; SerdURI uri; SerdURI abs_uri; serd_env_get_base_uri(writer->env, &in_base_uri); serd_uri_parse(node->buf, &uri); serd_uri_resolve(&uri, &in_base_uri, &abs_uri); bool rooted = uri_is_under(&writer->base_uri, &writer->root_uri); SerdURI* root = rooted ? &writer->root_uri : &writer->base_uri; UriSinkContext ctx = {writer, SERD_SUCCESS}; if (!uri_is_under(&abs_uri, root) || writer->syntax == SERD_NTRIPLES || writer->syntax == SERD_NQUADS) { serd_uri_serialise(&abs_uri, uri_sink, &ctx); } else { serd_uri_serialise_relative( &uri, &writer->base_uri, root, uri_sink, &ctx); } } else { TRY(st, write_uri_from_node(writer, node)); } return esink(">", 1, writer); } SERD_NODISCARD static SerdStatus write_curie(SerdWriter* const writer, const SerdNode* const node) { SerdChunk prefix = {NULL, 0}; SerdChunk suffix = {NULL, 0}; SerdStatus st = SERD_SUCCESS; // In fast-and-loose Turtle/TriG mode CURIEs are simply passed through const bool fast = !(writer->style & (SERD_STYLE_CURIED | SERD_STYLE_RESOLVED)); if (!supports_abbrev(writer) || !fast) { if ((st = serd_env_expand(writer->env, node, &prefix, &suffix))) { return w_err(writer, st, "undefined namespace prefix '%s'\n", node->buf); } } if (!supports_abbrev(writer)) { TRY(st, esink("<", 1, writer)); TRY(st, ewrite_uri(writer, prefix.buf, prefix.len)); TRY(st, ewrite_uri(writer, suffix.buf, suffix.len)); TRY(st, esink(">", 1, writer)); } else { TRY(st, write_lname(writer, node->buf, node->n_bytes)); } return st; } SERD_NODISCARD static SerdStatus write_blank(SerdWriter* const writer, const SerdNode* node, const Field field, const SerdStatementFlags flags) { SerdStatus st = SERD_SUCCESS; if (supports_abbrev(writer)) { if ((field == FIELD_SUBJECT && (flags & SERD_ANON_S_BEGIN)) || (field == FIELD_OBJECT && (flags & SERD_ANON_O_BEGIN))) { return write_sep(writer, SEP_ANON_BEGIN); } if ((field == FIELD_SUBJECT && (flags & SERD_LIST_S_BEGIN)) || (field == FIELD_OBJECT && (flags & SERD_LIST_O_BEGIN))) { return write_sep(writer, SEP_LIST_BEGIN); } if ((field == FIELD_SUBJECT && (flags & SERD_EMPTY_S)) || (field == FIELD_OBJECT && (flags & SERD_EMPTY_O))) { return esink("[]", 2, writer); } } TRY(st, esink("_:", 2, writer)); if (writer->bprefix && !strncmp((const char*)node->buf, (const char*)writer->bprefix, writer->bprefix_len)) { TRY(st, esink(node->buf + writer->bprefix_len, node->n_bytes - writer->bprefix_len, writer)); } else { TRY(st, esink(node->buf, node->n_bytes, writer)); } return st; } SERD_NODISCARD static SerdStatus write_node(SerdWriter* writer, const SerdNode* node, const SerdNode* datatype, const SerdNode* lang, Field field, SerdStatementFlags flags) { SerdStatus st = SERD_SUCCESS; switch (node->type) { case SERD_NOTHING: break; case SERD_LITERAL: st = write_literal(writer, node, datatype, lang, flags); break; case SERD_URI: st = write_uri_node(writer, node, field); break; case SERD_CURIE: st = write_curie(writer, node); break; case SERD_BLANK: st = write_blank(writer, node, field, flags); break; } if (node->type != SERD_BLANK) { writer->last_sep = SEP_NODE; } return st; } static bool is_resource(const SerdNode* node) { return node && node->buf && node->type > SERD_LITERAL; } SERD_NODISCARD static SerdStatus write_pred(SerdWriter* writer, SerdStatementFlags flags, const SerdNode* pred) { SerdStatus st = SERD_SUCCESS; TRY(st, write_node(writer, pred, NULL, NULL, FIELD_PREDICATE, flags)); TRY(st, write_sep(writer, SEP_P_O)); copy_node(&writer->context.predicate, pred); writer->context.predicates = true; writer->context.comma_indented = false; return st; } SERD_NODISCARD static SerdStatus write_list_next(SerdWriter* writer, SerdStatementFlags flags, const SerdNode* predicate, const SerdNode* object, const SerdNode* datatype, const SerdNode* lang) { SerdStatus st = SERD_SUCCESS; if (!strcmp((const char*)object->buf, NS_RDF "nil")) { TRY(st, write_sep(writer, SEP_LIST_END)); return SERD_FAILURE; } if (!strcmp((const char*)predicate->buf, NS_RDF "first")) { TRY(st, write_node(writer, object, datatype, lang, FIELD_OBJECT, flags)); } else { TRY(st, write_sep(writer, SEP_LIST_SEP)); } return st; } SERD_NODISCARD static SerdStatus terminate_context(SerdWriter* writer) { SerdStatus st = SERD_SUCCESS; if (writer->context.subject.type) { TRY(st, write_sep(writer, SEP_END_S)); } if (writer->context.graph.type) { TRY(st, write_sep(writer, SEP_GRAPH_END)); } return st; } SerdStatus serd_writer_write_statement(SerdWriter* writer, SerdStatementFlags flags, const SerdNode* graph, const SerdNode* subject, const SerdNode* predicate, const SerdNode* object, const SerdNode* datatype, const SerdNode* lang) { SerdStatus st = SERD_SUCCESS; if (!is_resource(subject) || !is_resource(predicate) || !object || !object->buf) { return SERD_ERR_BAD_ARG; } // Simple case: write a line of NTriples or NQuads if (writer->syntax == SERD_NTRIPLES || writer->syntax == SERD_NQUADS) { TRY(st, write_node(writer, subject, NULL, NULL, FIELD_SUBJECT, flags)); TRY(st, esink(" ", 1, writer)); TRY(st, write_node(writer, predicate, NULL, NULL, FIELD_PREDICATE, flags)); TRY(st, esink(" ", 1, writer)); TRY(st, write_node(writer, object, datatype, lang, FIELD_OBJECT, flags)); if (writer->syntax == SERD_NQUADS && graph) { TRY(st, esink(" ", 1, writer)); TRY(st, write_node(writer, graph, datatype, lang, FIELD_GRAPH, flags)); } TRY(st, esink(" .\n", 3, writer)); return SERD_SUCCESS; } // Separate graphs if necessary if ((graph && !serd_node_equals(graph, &writer->context.graph)) || (!graph && writer->context.graph.type)) { TRY(st, terminate_context(writer)); reset_context(writer, RESET_GRAPH | RESET_INDENT); if (graph) { TRY(st, write_newline(writer)); TRY(st, write_node(writer, graph, datatype, lang, FIELD_GRAPH, flags)); TRY(st, write_sep(writer, SEP_GRAPH_BEGIN)); copy_node(&writer->context.graph, graph); } } if ((flags & SERD_LIST_CONT)) { // Continue a list if (!strcmp((const char*)predicate->buf, NS_RDF "first") && !strcmp((const char*)object->buf, NS_RDF "nil")) { return esink("()", 2, writer); } TRY_FAILING( st, write_list_next(writer, flags, predicate, object, datatype, lang)); if (st == SERD_FAILURE) { // Reached end of list pop_context(writer); return SERD_SUCCESS; } } else if (serd_node_equals(subject, &writer->context.subject)) { if (serd_node_equals(predicate, &writer->context.predicate)) { // Elide S P (write O) const Sep last = writer->last_sep; const bool anon_o = flags & SERD_ANON_O_BEGIN; const bool list_o = flags & SERD_LIST_O_BEGIN; const bool open_o = anon_o || list_o; const bool after_end = (last == SEP_ANON_END) || (last == SEP_LIST_END); TRY(st, write_sep(writer, after_end ? (open_o ? SEP_JOIN_O_AA : SEP_JOIN_O_AN) : (open_o ? SEP_JOIN_O_NA : SEP_END_O))); } else { // Elide S (write P and O) if (writer->context.comma_indented) { --writer->indent; writer->context.comma_indented = false; } const bool first = !writer->context.predicate.type; TRY(st, write_sep(writer, first ? SEP_S_P : SEP_END_P)); TRY(st, write_pred(writer, flags, predicate)); } TRY(st, write_node(writer, object, datatype, lang, FIELD_OBJECT, flags)); } else { // No abbreviation if (serd_stack_is_empty(&writer->anon_stack)) { if (writer->context.subject.type) { TRY(st, write_sep(writer, SEP_END_S)); } if (writer->last_sep == SEP_END_S || writer->last_sep == SEP_END_DIRECT) { TRY(st, write_newline(writer)); } TRY(st, write_node(writer, subject, NULL, NULL, FIELD_SUBJECT, flags)); if ((flags & (SERD_ANON_S_BEGIN | SERD_LIST_S_BEGIN))) { TRY(st, write_sep(writer, SEP_ANON_S_P)); } else { TRY(st, write_sep(writer, SEP_S_P)); } } else { TRY(st, write_sep(writer, SEP_ANON_S_P)); } reset_context(writer, 0U); copy_node(&writer->context.subject, subject); if (!(flags & SERD_LIST_S_BEGIN)) { TRY(st, write_pred(writer, flags, predicate)); } TRY(st, write_node(writer, object, datatype, lang, FIELD_OBJECT, flags)); } if (flags & (SERD_ANON_S_BEGIN | SERD_LIST_S_BEGIN)) { // Push context for anonymous or list subject const bool is_list = (flags & SERD_LIST_S_BEGIN); push_context(writer, is_list ? CTX_LIST : CTX_BLANK, serd_node_copy(graph), serd_node_copy(subject), is_list ? SERD_NODE_NULL : serd_node_copy(predicate)); } if (flags & (SERD_ANON_O_BEGIN | SERD_LIST_O_BEGIN)) { // Push context for anonymous or list object if necessary push_context(writer, (flags & SERD_LIST_O_BEGIN) ? CTX_LIST : CTX_BLANK, serd_node_copy(graph), serd_node_copy(object), SERD_NODE_NULL); } return st; } SerdStatus serd_writer_end_anon(SerdWriter* writer, const SerdNode* node) { SerdStatus st = SERD_SUCCESS; if (writer->syntax == SERD_NTRIPLES || writer->syntax == SERD_NQUADS) { return SERD_SUCCESS; } if (serd_stack_is_empty(&writer->anon_stack)) { return w_err( writer, SERD_ERR_UNKNOWN, "unexpected end of anonymous node\n"); } // Write the end separator ']' and pop the context TRY(st, write_sep(writer, SEP_ANON_END)); pop_context(writer); if (serd_node_equals(node, &writer->context.subject)) { // Now-finished anonymous node is the new subject with no other context writer->context.predicate.type = SERD_NOTHING; } return st; } SerdStatus serd_writer_finish(SerdWriter* writer) { const SerdStatus st0 = terminate_context(writer); const SerdStatus st1 = serd_byte_sink_flush(&writer->byte_sink); free_anon_stack(writer); reset_context(writer, RESET_GRAPH | RESET_INDENT); return st0 ? st0 : st1; } SerdWriter* serd_writer_new(SerdSyntax syntax, SerdStyle style, SerdEnv* env, const SerdURI* base_uri, SerdSink ssink, void* stream) { const WriteContext context = WRITE_CONTEXT_NULL; SerdWriter* writer = (SerdWriter*)calloc(1, sizeof(SerdWriter)); writer->syntax = syntax; writer->style = style; writer->env = env; writer->root_node = SERD_NODE_NULL; writer->root_uri = SERD_URI_NULL; writer->base_uri = base_uri ? *base_uri : SERD_URI_NULL; writer->anon_stack = serd_stack_new(SERD_PAGE_SIZE); writer->context = context; writer->byte_sink = serd_byte_sink_new( ssink, stream, (style & SERD_STYLE_BULK) ? SERD_PAGE_SIZE : 1); return writer; } void serd_writer_set_error_sink(SerdWriter* writer, SerdErrorSink error_sink, void* error_handle) { writer->error_sink = error_sink; writer->error_handle = error_handle; } void serd_writer_chop_blank_prefix(SerdWriter* writer, const uint8_t* prefix) { free(writer->bprefix); writer->bprefix_len = 0; writer->bprefix = NULL; const size_t prefix_len = prefix ? strlen((const char*)prefix) : 0; if (prefix_len) { writer->bprefix_len = prefix_len; writer->bprefix = (uint8_t*)malloc(writer->bprefix_len + 1); memcpy(writer->bprefix, prefix, writer->bprefix_len + 1); } } SerdStatus serd_writer_set_base_uri(SerdWriter* writer, const SerdNode* uri) { SerdStatus st = SERD_SUCCESS; TRY(st, serd_env_set_base_uri(writer->env, uri)); serd_env_get_base_uri(writer->env, &writer->base_uri); if (uri && (writer->syntax == SERD_TURTLE || writer->syntax == SERD_TRIG)) { TRY(st, terminate_context(writer)); TRY(st, esink("@base <", 7, writer)); TRY(st, esink(uri->buf, uri->n_bytes, writer)); TRY(st, esink(">", 1, writer)); writer->last_sep = SEP_NODE; TRY(st, write_sep(writer, SEP_END_DIRECT)); } return reset_context(writer, RESET_GRAPH | RESET_INDENT); } SerdStatus serd_writer_set_root_uri(SerdWriter* writer, const SerdNode* uri) { serd_node_free(&writer->root_node); if (uri && uri->buf) { writer->root_node = serd_node_copy(uri); serd_uri_parse(uri->buf, &writer->root_uri); } else { writer->root_node = SERD_NODE_NULL; writer->root_uri = SERD_URI_NULL; } return SERD_SUCCESS; } SerdStatus serd_writer_set_prefix(SerdWriter* writer, const SerdNode* name, const SerdNode* uri) { SerdStatus st = SERD_SUCCESS; TRY(st, serd_env_set_prefix(writer->env, name, uri)); if (writer->syntax == SERD_TURTLE || writer->syntax == SERD_TRIG) { TRY(st, terminate_context(writer)); TRY(st, esink("@prefix ", 8, writer)); TRY(st, esink(name->buf, name->n_bytes, writer)); TRY(st, esink(": <", 3, writer)); TRY(st, ewrite_uri(writer, uri->buf, uri->n_bytes)); TRY(st, esink(">", 1, writer)); writer->last_sep = SEP_NODE; TRY(st, write_sep(writer, SEP_END_DIRECT)); } return reset_context(writer, RESET_GRAPH | RESET_INDENT); } void serd_writer_free(SerdWriter* writer) { if (!writer) { return; } serd_writer_finish(writer); free_context(&writer->context); free_anon_stack(writer); serd_stack_free(&writer->anon_stack); free(writer->bprefix); serd_byte_sink_free(&writer->byte_sink); serd_node_free(&writer->root_node); free(writer); } SerdEnv* serd_writer_get_env(SerdWriter* writer) { return writer->env; } size_t serd_file_sink(const void* buf, size_t len, void* stream) { return fwrite(buf, 1, len, (FILE*)stream); } size_t serd_chunk_sink(const void* buf, size_t len, void* stream) { SerdChunk* chunk = (SerdChunk*)stream; uint8_t* new_buf = (uint8_t*)realloc((uint8_t*)chunk->buf, chunk->len + len); if (new_buf) { memcpy(new_buf + chunk->len, buf, len); chunk->buf = new_buf; chunk->len += len; } return len; } uint8_t* serd_chunk_sink_finish(SerdChunk* stream) { serd_chunk_sink("", 1, stream); return (uint8_t*)stream->buf; }