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//
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// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
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// contributors may be used to endorse or promote products derived from
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//
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef NET_HTTP_HTTP_UTIL_H_
#define NET_HTTP_HTTP_UTIL_H_
#include "base/string_tokenizer.h"
// This is a macro to support extending this string literal at compile time.
// Please excuse me polluting your global namespace!
#define HTTP_LWS " \t"
namespace net {
class HttpUtil {
public:
// Locates the next occurance of delimiter in line, skipping over quoted
// strings (e.g., commas will not be treated as delimiters if they appear
// within a quoted string). Returns the offset of the found delimiter or
// line.size() if no delimiter was found.
static size_t FindDelimiter(const std::string& line,
size_t search_start,
char delimiter);
// Parses the value of a Content-Type header. The resulting mime_type and
// charset values are normalized to lowercase. The mime_type and charset
// output values are only modified if the content_type_str contains a mime
// type and charset value, respectively.
static void ParseContentType(const std::string& content_type_str,
std::string* mime_type,
std::string* charset,
bool *had_charset);
// Scans the '\r\n'-delimited headers for the given header name. Returns
// true if a match is found. Input is assumed to be well-formed.
// TODO(darin): kill this
static bool HasHeader(const std::string& headers, const char* name);
// Multiple occurances of some headers cannot be coalesced into a comma-
// separated list since their values are (or contain) unquoted HTTP-date
// values, which may contain a comma (see RFC 2616 section 3.3.1).
static bool IsNonCoalescingHeader(std::string::const_iterator name_begin,
std::string::const_iterator name_end);
static bool IsNonCoalescingHeader(const std::string& name) {
return IsNonCoalescingHeader(name.begin(), name.end());
}
// Trim HTTP_LWS chars from the beginning and end of the string.
static void TrimLWS(std::string::const_iterator* begin,
std::string::const_iterator* end);
// Returns index beyond the end-of-headers marker or -1 if not found. RFC
// 2616 defines the end-of-headers marker as a double CRLF; however, some
// servers only send back LFs (e.g., Unix-based CGI scripts written using the
// ASIS Apache module). This function therefore accepts the pattern LF[CR]LF
// as end-of-headers (just like Mozilla).
static int LocateEndOfHeaders(const char* buf, int buf_len);
// Assemble "raw headers" in the format required by HttpResponseHeaders.
// This involves normalizing line terminators, converting [CR]LF to \0 and
// handling HTTP line continuations (i.e., lines starting with LWS are
// continuations of the previous line). |buf_len| indicates the position of
// the end-of-headers marker as defined by LocateEndOfHeaders.
static std::string AssembleRawHeaders(const char* buf, int buf_len);
// Used to iterate over the name/value pairs of HTTP headers. To iterate
// over the values in a multi-value header, use ValuesIterator.
class HeadersIterator {
public:
HeadersIterator(std::string::const_iterator headers_begin,
std::string::const_iterator headers_end,
const std::string& line_delimiter);
// Advances the iterator to the next header, if any. Returns true if there
// is a next header. Use name* and values* methods to access the resultant
// header name and values.
bool GetNext();
std::string::const_iterator name_begin() const {
return name_begin_;
}
std::string::const_iterator name_end() const {
return name_end_;
}
std::string name() const {
return std::string(name_begin_, name_end_);
}
std::string::const_iterator values_begin() const {
return values_begin_;
}
std::string::const_iterator values_end() const {
return values_end_;
}
std::string values() const {
return std::string(values_begin_, values_end_);
}
private:
StringTokenizer lines_;
std::string::const_iterator name_begin_;
std::string::const_iterator name_end_;
std::string::const_iterator values_begin_;
std::string::const_iterator values_end_;
};
// Used to iterate over deliminated values in a HTTP header. HTTP LWS is
// automatically trimmed from the resulting values.
//
// When using this class to iterate over response header values, beware that
// for some headers (e.g., Last-Modified), commas are not used as delimiters.
// This iterator should be avoided for headers like that which are considered
// non-coalescing (see IsNonCoalescingHeader).
//
// This iterator is careful to skip over delimiters found inside an HTTP
// quoted string.
//
class ValuesIterator {
public:
ValuesIterator(std::string::const_iterator values_begin,
std::string::const_iterator values_end,
char delimiter);
// Advances the iterator to the next value, if any. Returns true if there
// is a next value. Use value* methods to access the resultant value.
bool GetNext();
std::string::const_iterator value_begin() const {
return value_begin_;
}
std::string::const_iterator value_end() const {
return value_end_;
}
std::string value() const {
return std::string(value_begin_, value_end_);
}
private:
StringTokenizer values_;
std::string::const_iterator value_begin_;
std::string::const_iterator value_end_;
};
};
} // namespace net
#endif // NET_HTTP_HTTP_UTIL_H_