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Diffstat (limited to 'src/uri.c')
-rw-r--r-- | src/uri.c | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/src/uri.c b/src/uri.c new file mode 100644 index 00000000..249b2674 --- /dev/null +++ b/src/uri.c @@ -0,0 +1,512 @@ +/* + Copyright 2011-2014 David Robillard <http://drobilla.net> + + 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 "serd_internal.h" + +#include <stdlib.h> +#include <string.h> + +// #define URI_DEBUG 1 + +const uint8_t* +serd_uri_to_path(const uint8_t* uri) +{ + const uint8_t* path = uri; + if (!is_windows_path(uri) && serd_uri_string_has_scheme(uri)) { + if (strncmp((const char*)uri, "file:", 5)) { + fprintf(stderr, "Non-file URI `%s'\n", uri); + return NULL; + } else if (!strncmp((const char*)uri, "file://localhost/", 17)) { + path = uri + 16; + } else if (!strncmp((const char*)uri, "file://", 7)) { + path = uri + 7; + } else { + fprintf(stderr, "Invalid file URI `%s'\n", uri); + return NULL; + } + if (is_windows_path(path + 1)) { + ++path; // Special case for terrible Windows file URIs + } + } + return path; +} + +uint8_t* +serd_file_uri_parse(const uint8_t* uri, uint8_t** hostname) +{ + const uint8_t* path = uri; + if (hostname) { + *hostname = NULL; + } + if (!strncmp((const char*)uri, "file://", 7)) { + const uint8_t* auth = uri + 7; + if (*auth == '/') { // No hostname + path = auth; + } else { // Has hostname + if (!(path = (const uint8_t*)strchr((const char*)auth, '/'))) { + return NULL; + } + if (hostname) { + *hostname = (uint8_t*)calloc(path - auth + 1, 1); + memcpy(*hostname, auth, path - auth); + } + } + } + + if (is_windows_path(path + 1)) { + ++path; + } + + SerdChunk chunk = { NULL, 0 }; + for (const uint8_t* s = path; *s; ++s) { + if (*s == '%') { + if (*(s + 1) == '%') { + serd_chunk_sink("%", 1, &chunk); + ++s; + } else if (is_hexdig(*(s + 1)) && is_hexdig(*(s + 2))) { + const uint8_t code[3] = { *(s + 1), *(s + 2), 0 }; + uint32_t num; + sscanf((const char*)code, "%X", &num); + const uint8_t c = num; + serd_chunk_sink(&c, 1, &chunk); + s += 2; + } else { + s += 2; // Junk escape, ignore + } + } else { + serd_chunk_sink(s, 1, &chunk); + } + } + return serd_chunk_sink_finish(&chunk); +} + +bool +serd_uri_string_has_scheme(const uint8_t* utf8) +{ + // RFC3986: scheme ::= ALPHA *( ALPHA / DIGIT / "+" / "-" / "." ) + if (!utf8 || !is_alpha(utf8[0])) { + return false; // Invalid scheme initial character, URI is relative + } + + for (uint8_t c; (c = *++utf8) != '\0';) { + if (!is_uri_scheme_char(c)) { + return false; + } else if (c == ':') { + return true; // End of scheme + } + } + + return false; +} + +#ifdef URI_DEBUG +static void +serd_uri_dump(const SerdURI* uri, FILE* file) +{ +#define PRINT_PART(range, name) \ + if (range.buf) { \ + fprintf(stderr, " " name " = "); \ + fwrite((range).buf, 1, (range).len, stderr); \ + fprintf(stderr, "\n"); \ + } + + PRINT_PART(uri->scheme, "scheme "); + PRINT_PART(uri->authority, "authority"); + PRINT_PART(uri->path_base, "path_base"); + PRINT_PART(uri->path, "path "); + PRINT_PART(uri->query, "query "); + PRINT_PART(uri->fragment, "fragment "); +} +#endif + +SerdStatus +serd_uri_parse(const uint8_t* utf8, SerdURI* out) +{ + *out = SERD_URI_NULL; + + const uint8_t* ptr = utf8; + + /* See http://tools.ietf.org/html/rfc3986#section-3 + URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ] + */ + + /* S3.1: scheme ::= ALPHA *( ALPHA / DIGIT / "+" / "-" / "." ) */ + if (is_alpha(*ptr)) { + for (uint8_t c = *++ptr; true; c = *++ptr) { + switch (c) { + case '\0': case '/': case '?': case '#': + ptr = utf8; + goto path; // Relative URI (starts with path by definition) + case ':': + out->scheme.buf = utf8; + out->scheme.len = (ptr++) - utf8; + goto maybe_authority; // URI with scheme + case '+': case '-': case '.': + continue; + default: + if (is_alpha(c) || is_digit(c)) { + continue; + } + } + } + } + + /* S3.2: The authority component is preceded by a double slash ("//") + and is terminated by the next slash ("/"), question mark ("?"), + or number sign ("#") character, or by the end of the URI. + */ +maybe_authority: + if (*ptr == '/' && *(ptr + 1) == '/') { + ptr += 2; + out->authority.buf = ptr; + for (uint8_t c; (c = *ptr) != '\0'; ++ptr) { + switch (c) { + case '/': goto path; + case '?': goto query; + case '#': goto fragment; + default: + ++out->authority.len; + } + } + } + + /* RFC3986 S3.3: The path is terminated by the first question mark ("?") + or number sign ("#") character, or by the end of the URI. + */ +path: + switch (*ptr) { + case '?': goto query; + case '#': goto fragment; + case '\0': goto end; + default: break; + } + out->path.buf = ptr; + out->path.len = 0; + for (uint8_t c; (c = *ptr) != '\0'; ++ptr) { + switch (c) { + case '?': goto query; + case '#': goto fragment; + default: + ++out->path.len; + } + } + + /* RFC3986 S3.4: The query component is indicated by the first question + mark ("?") character and terminated by a number sign ("#") character + or by the end of the URI. + */ +query: + if (*ptr == '?') { + out->query.buf = ++ptr; + for (uint8_t c; (c = *ptr) != '\0'; ++ptr) { + switch (c) { + case '#': + goto fragment; + default: + ++out->query.len; + } + } + } + + /* RFC3986 S3.5: A fragment identifier component is indicated by the + presence of a number sign ("#") character and terminated by the end + of the URI. + */ +fragment: + if (*ptr == '#') { + out->fragment.buf = ptr; + while (*ptr++ != '\0') { + ++out->fragment.len; + } + } + +end: + #ifdef URI_DEBUG + fprintf(stderr, "PARSE URI <%s>\n", utf8); + serd_uri_dump(out, stderr); + fprintf(stderr, "\n"); + #endif + + return SERD_SUCCESS; +} + +/** + Remove leading dot components from `path`. + See http://tools.ietf.org/html/rfc3986#section-5.2.3 + @param up Set to the number of up-references (e.g. "../") trimmed + @return A pointer to the new start of `path` +*/ +static const uint8_t* +remove_dot_segments(const uint8_t* path, size_t len, size_t* up) +{ + const uint8_t* begin = path; + const uint8_t* const end = path + len; + + *up = 0; + while (begin < end) { + switch (begin[0]) { + case '.': + switch (begin[1]) { + case '/': + begin += 2; // Chop leading "./" + break; + case '.': + switch (begin[2]) { + case '\0': + ++*up; + begin += 2; // Chop input ".." + break; + case '/': + ++*up; + begin += 3; // Chop leading "../" + break; + default: + return begin; + } + break; + case '\0': + ++begin; // Chop input "." + // fallthru + default: + return begin; + } + break; + case '/': + switch (begin[1]) { + case '.': + switch (begin[2]) { + case '/': + begin += 2; // Leading "/./" => "/" + break; + case '.': + switch (begin[3]) { + case '/': + ++*up; + begin += 3; // Leading "/../" => "/" + } + break; + default: + return begin; + } + } // else fall through + default: + return begin; // Finished chopping dot components + } + } + + return begin; +} + +/// Merge `base` and `path` in-place +static void +merge(SerdChunk* base, SerdChunk* path) +{ + size_t up; + const uint8_t* begin = remove_dot_segments(path->buf, path->len, &up); + const uint8_t* end = path->buf + path->len; + + if (base->len) { + // Find the up'th last slash + const uint8_t* base_last = (base->buf + base->len - 1); + ++up; + do { + if (*base_last == '/') { + --up; + } + } while (up > 0 && (--base_last > base->buf)); + + // Set path prefix + base->len = base_last - base->buf + 1; + } + + // Set path suffix + path->buf = begin; + path->len = end - begin; +} + +/// See http://tools.ietf.org/html/rfc3986#section-5.2.2 +void +serd_uri_resolve(const SerdURI* r, const SerdURI* base, SerdURI* t) +{ + if (!base->scheme.len) { + *t = *r; // Don't resolve against non-absolute URIs + return; + } + + t->path_base.buf = NULL; + t->path_base.len = 0; + if (r->scheme.len) { + *t = *r; + } else { + if (r->authority.len) { + t->authority = r->authority; + t->path = r->path; + t->query = r->query; + } else { + t->path = r->path; + if (!r->path.len) { + t->path_base = base->path; + if (r->query.len) { + t->query = r->query; + } else { + t->query = base->query; + } + } else { + if (r->path.buf[0] != '/') { + t->path_base = base->path; + } + merge(&t->path_base, &t->path); + t->query = r->query; + } + t->authority = base->authority; + } + t->scheme = base->scheme; + t->fragment = r->fragment; + } + + #ifdef URI_DEBUG + fprintf(stderr, "## RESOLVE URI\n# BASE\n"); + serd_uri_dump(base, stderr); + fprintf(stderr, "# URI\n"); + serd_uri_dump(r, stderr); + fprintf(stderr, "# RESULT\n"); + serd_uri_dump(t, stderr); + fprintf(stderr, "\n"); + #endif +} + +/** Write the path of `uri` starting at index `i` */ +static size_t +write_path_tail(SerdSink sink, void* stream, const SerdURI* uri, size_t i) +{ + size_t len = 0; + if (i < uri->path_base.len) { + len += sink(uri->path_base.buf + i, uri->path_base.len - i, stream); + } + if (uri->path.buf) { + if (i < uri->path_base.len) { + len += sink(uri->path.buf, uri->path.len, stream); + } else { + const size_t j = (i - uri->path_base.len); + len += sink(uri->path.buf + j, uri->path.len - j, stream); + } + } + return len; +} + +/** Write the path of `uri` relative to the path of `base`. */ +static size_t +write_rel_path(SerdSink sink, + void* stream, + const SerdURI* uri, + const SerdURI* base) +{ + const size_t path_len = uri_path_len(uri); + const size_t base_len = uri_path_len(base); + const size_t min_len = (path_len < base_len) ? path_len : base_len; + + // Find the last separator common to both paths + size_t last_shared_sep = 0; + size_t i = 0; + for (; i < min_len && uri_path_at(uri, i) == uri_path_at(base, i); ++i) { + if (uri_path_at(uri, i) == '/') { + last_shared_sep = i; + } + } + + if (i == path_len && i == base_len) { // Paths are identical + return 0; + } + + // Find the number of up references ("..") required + size_t up = 0; + for (size_t s = last_shared_sep + 1; s < base_len; ++s) { + if (uri_path_at(base, s) == '/') { + ++up; + } + } + + // Write up references + size_t len = 0; + for (size_t u = 0; u < up; ++u) { + len += sink("../", 3, stream); + } + + if (last_shared_sep == 0 && up == 0) { + len += sink("/", 1, stream); + } + + // Write suffix + return len += write_path_tail(sink, stream, uri, last_shared_sep + 1); +} + +static uint8_t +serd_uri_path_starts_without_slash(const SerdURI* uri) +{ + return ((uri->path_base.len || uri->path.len) && + ((!uri->path_base.len || uri->path_base.buf[0] != '/') && + (!uri->path.len || uri->path.buf[0] != '/'))); +} + +/// See http://tools.ietf.org/html/rfc3986#section-5.3 +size_t +serd_uri_serialise_relative(const SerdURI* uri, + const SerdURI* base, + const SerdURI* root, + SerdSink sink, + void* stream) +{ + size_t len = 0; + const bool relative = + root ? uri_is_under(uri, root) : uri_is_related(uri, base); + + if (relative) { + len = write_rel_path(sink, stream, uri, base); + } + if (!relative || (!len && base->query.buf)) { + if (uri->scheme.buf) { + len += sink(uri->scheme.buf, uri->scheme.len, stream); + len += sink(":", 1, stream); + } + if (uri->authority.buf) { + len += sink("//", 2, stream); + len += sink(uri->authority.buf, uri->authority.len, stream); + if (uri->authority.buf[uri->authority.len - 1] != '/' && + serd_uri_path_starts_without_slash(uri)) { + // Special case: ensure path begins with a slash + // https://tools.ietf.org/html/rfc3986#section-3.2 + len += sink("/", 1, stream); + } + } + len += write_path_tail(sink, stream, uri, 0); + } + if (uri->query.buf) { + len += sink("?", 1, stream); + len += sink(uri->query.buf, uri->query.len, stream); + } + if (uri->fragment.buf) { + // Note uri->fragment.buf includes the leading `#' + len += sink(uri->fragment.buf, uri->fragment.len, stream); + } + return len; +} + +/// See http://tools.ietf.org/html/rfc3986#section-5.3 +size_t +serd_uri_serialise(const SerdURI* uri, SerdSink sink, void* stream) +{ + return serd_uri_serialise_relative(uri, NULL, NULL, sink, stream); +} |