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Diffstat (limited to 'libbutl/curl.hxx')
| -rw-r--r-- | libbutl/curl.hxx | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/libbutl/curl.hxx b/libbutl/curl.hxx new file mode 100644 index 0000000..cd4ebd0 --- /dev/null +++ b/libbutl/curl.hxx @@ -0,0 +1,171 @@ +// file : libbutl/curl.hxx -*- C++ -*- +// license : MIT; see accompanying LICENSE file + +#pragma once + +#include <string> +#include <type_traits> + +#include <libbutl/path.hxx> +#include <libbutl/process.hxx> +#include <libbutl/fdstream.hxx> +#include <libbutl/small-vector.hxx> + +#include <libbutl/export.hxx> + +namespace butl +{ + // Perform a method (GET, POST, PUT) on a URL using the curl(1) program. + // Throw process_error and io_error (both derive from system_error) in case + // of errors. + // + // The I (in) and O (out) can be of the following types/values: + // + // nullfd Signal that no input/output is expected. + // + // path Read input/write output from/to a file. If the special "-" + // value is used, then instead input is connected to the curl::out + // ofdstream member and output -- to the curl::in ifdstream member. + // Note that the argument type should be path, not string (i.e., + // pass path("-")). + // + // other Forwarded as is to process_start(). Normally either int or + // auto_fd. + // + // For example: + // + // curl (nullfd, // No input expected for GET. + // path ("-"), // Write response to curl::in. + // 2, + // curl::get, + // "http://example.org"); + // + // curl (path ("-"), // Read request from curl::out. + // path::temp_path (), // Write result to a file. + // 2, + // curl::post, + // "http://example.org"); + // + // curl (nullfd, + // fdopen_null (), // Write result to /dev/null. + // 2, + // curl::get, + // "tftp://localhost/foo"); + // + // Typical usage: + // + // try + // { + // curl c (nullfd, // No input expected. + // path ("-"), // Output to curl::in. + // 2, // Diagnostics to stderr. + // curl::get, // GET method. + // "https://example.org", + // "-A", "foobot/1.2.3"); // Additional curl(1) options. + // + // for (string s; getline (c.in, s); ) + // cout << s << endl; + // + // c.in.close (); + // + // if (!c.wait ()) + // ... // curl returned non-zero status. + // } + // catch (const std::system_error& e) + // { + // cerr << "curl error: " << e << endl; + // } + // + // Notes: + // + // 1. If opened, in/out streams are in the binary mode. + // + // 2. If opened, in/out must be explicitly closed before calling wait(). + // + // 3. Only binary data HTTP POST is currently supported (the --data-binary + // curl option). + // + class LIBBUTL_SYMEXPORT curl: public process + { + public: + enum method_type {get, put, post}; + + ifdstream in; + ofdstream out; + + template <typename I, + typename O, + typename E, + typename... A> + curl (I&& in, + O&& out, + E&& err, + method_type, + const std::string& url, + A&&... options); + + // Version with the command line callback (see process_run_callback() for + // details). + // + template <typename C, + typename I, + typename O, + typename E, + typename... A> + curl (const C&, + I&& in, + O&& out, + E&& err, + method_type, + const std::string& url, + A&&... options); + + private: + enum method_proto {ftp_get, ftp_put, http_get, http_post}; + using method_proto_options = small_vector<const char*, 2>; + + method_proto + translate (method_type, const std::string& url, method_proto_options&); + + private: + template <typename T> + struct is_other + { + using type = typename std::remove_reference< + typename std::remove_cv<T>::type>::type; + + static const bool value = !(std::is_same<type, nullfd_t>::value || + std::is_same<type, path>::value); + }; + + struct io_data + { + fdpipe pipe; + method_proto_options options; + std::string storage; + }; + + pipe + map_in (nullfd_t, method_proto, io_data&); + + pipe + map_in (const path&, method_proto, io_data&); + + template <typename I> + typename std::enable_if<is_other<I>::value, I>::type + map_in (I&&, method_proto, io_data&); + + pipe + map_out (nullfd_t, method_proto, io_data&); + + pipe + map_out (const path&, method_proto, io_data&); + + template <typename O> + typename std::enable_if<is_other<O>::value, O>::type + map_out (O&&, method_proto, io_data&); + }; +} + +#include <libbutl/curl.ixx> +#include <libbutl/curl.txx> |