#include "codec/codec_nt.h" /** @brief List of characters to be escaped in serialized literals. * * @sa https://www.w3.org/TR/n-triples/#grammar-production-ECHAR */ #define LIT_ECHAR "\t\b\n\r\f\"\'\\" /** @brief Regex of characters to be escaped in serialized IRIs. * * @sa https://www.w3.org/TR/n-triples/#grammar-production-IRIREF */ #define IRI_ECHAR_PTN "[\x00-\x20<>\"\\{\\}\\|\\^`\\\\]" /* * * Static prototypes. * * */ static LSUP_rc escape_lit (const char *in, char **out_p); /* * * Codec functions. * * */ static LSUP_rc term_to_nt (const LSUP_Term *term, const LSUP_NSMap *nsm, char **out_p) { LSUP_rc rc; char *out = NULL, *escaped; const char *metadata = NULL; size_t buf_len; // Free previous content if not NULL. if (*out_p != NULL) out = realloc (*out_p, 0); char *data = term->data; switch (term->type) { case LSUP_TERM_NS_IRIREF: LSUP_nsmap_normalize_uri (nsm, term->data, &data); case LSUP_TERM_IRIREF: out = realloc (out, strlen (data) + 3); if (UNLIKELY (!out)) return LSUP_MEM_ERR; sprintf (out, "<%s>", data); if (data != term->data) free (data); rc = LSUP_OK; break; case LSUP_TERM_LITERAL: // Calculate string length. if (escape_lit (term->data, &escaped) != LSUP_OK) return LSUP_ERROR; buf_len = strlen (escaped) + 3; // Room for "" and terminator if ( term->datatype != 0 && term->datatype != LSUP_default_datatype ) { metadata = term->datatype->data; buf_len += strlen (metadata) + 4; // Room for ^^<> } out = realloc (out, buf_len); if (UNLIKELY (!out)) return LSUP_MEM_ERR; sprintf (out, "\"%s\"", escaped); free (escaped); // Add datatype. if (metadata) out = strcat (strcat (strcat (out, "^^<"), metadata), ">"); rc = LSUP_OK; break; case LSUP_TERM_LT_LITERAL: // Calculate string length. if (escape_lit (term->data, &escaped) != LSUP_OK) return LSUP_ERROR; buf_len = strlen (escaped) + 3; // Room for "" and terminator if (term->lang != 0) { metadata = term->lang; buf_len += strlen (metadata) + 1; // Room for @ } out = realloc (out, buf_len); if (UNLIKELY (!out)) return LSUP_MEM_ERR; sprintf (out, "\"%s\"", escaped); free (escaped); // Add lang. if (metadata) out = strcat (strcat (out, "@"), metadata); rc = LSUP_OK; break; case LSUP_TERM_BNODE: out = realloc (out, strlen (term->data) + 3); if (UNLIKELY (!out)) return LSUP_MEM_ERR; sprintf (out, "_:%s", term->data); rc = LSUP_OK; break; default: out = NULL; rc = LSUP_VALUE_ERR; } *out_p = out; return rc; } static LSUP_CodecIterator * gr_to_nt_init (const LSUP_Graph *gr); static LSUP_rc gr_to_nt_iter (LSUP_CodecIterator *it, unsigned char **res) { LSUP_rc rc = LSUP_graph_iter_next (it->gr_it, it->trp); if (rc != LSUP_OK) goto finally; term_to_nt (it->trp->s, it->nsm, &it->str_s); term_to_nt (it->trp->p, it->nsm, &it->str_p); term_to_nt (it->trp->o, it->nsm, &it->str_o); // 3 term separators + dot + newline + terminal = 6 unsigned char *tmp = realloc ( *res, strlen (it->str_s) + strlen (it->str_p) + strlen (it->str_o) + 6); if (UNLIKELY (!tmp)) { *res = NULL; rc = LSUP_MEM_ERR; goto finally; } sprintf ((char*)tmp, "%s %s %s .\n", it->str_s, it->str_p, it->str_o); *res = tmp; it->cur++; finally: LSUP_term_free (it->trp->s); it->trp->s = NULL; LSUP_term_free (it->trp->p); it->trp->p = NULL; LSUP_term_free (it->trp->o); it->trp->o = NULL; return rc; } static void gr_to_nt_done (LSUP_CodecIterator *it) { LSUP_graph_iter_free (it->gr_it); LSUP_triple_free (it->trp); free (it->rep); free (it->str_s); free (it->str_p); free (it->str_o); free (it); } const LSUP_Codec nt_codec = { .name = "N-Triples", .mimetype = "application/n-triples", .extension = "nt", .encode_term = term_to_nt, .encode_graph_init = gr_to_nt_init, .encode_graph_iter = gr_to_nt_iter, .encode_graph_done = gr_to_nt_done, .decode_term = LSUP_nt_parse_term, .decode_graph = LSUP_nt_parse_doc, }; /* * * Other static functions. * * */ static LSUP_CodecIterator * gr_to_nt_init (const LSUP_Graph *gr) { LSUP_CodecIterator *it; MALLOC_GUARD (it, NULL); it->codec = &nt_codec; it->gr_it = LSUP_graph_lookup(gr, NULL, NULL, NULL, &it->cur); it->nsm = LSUP_graph_namespace (gr); it->cur = 0; it->trp = TRP_DUMMY; it->rep = NULL; it->str_s = NULL; it->str_p = NULL; it->str_o = NULL; return it; } /** @brief Add escape character (backslash) to illegal literal characters. */ static LSUP_rc escape_lit (const char *in, char **out_p) { size_t out_size = strlen (in) + 1; // Expand output string size to accommodate escape characters. for ( size_t i = strcspn (in, LIT_ECHAR); i < strlen (in); i += strcspn (in + i + 1, LIT_ECHAR) + 1) { out_size ++; } char *out = calloc (1, out_size); if (UNLIKELY (!out)) return LSUP_MEM_ERR; size_t boundary; boundary = strcspn (in, LIT_ECHAR); for (size_t i = 0, j = 0;;) { out = strncat (out, in + i, boundary); i += boundary; j += boundary; if (i >= strlen (in)) break; out[j++] = '\\'; out[j++] = escape_char (in[i++]); boundary = strcspn (in + i, LIT_ECHAR); } *out_p = out; return 0; }