Add C API to get HTTP responses

Author: link2xt

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Changes
 - Add `get_http_response` JSON-RPC API.
+- Add C API to get HTTP responses.
 
 ## [1.112.7] - 2023-04-17
 

deltachat-ffi/deltachat.h

@@ -25,6 +25,7 @@ typedef struct _dc_event     dc_event_t;
 typedef struct _dc_event_emitter dc_event_emitter_t;
 typedef struct _dc_jsonrpc_instance dc_jsonrpc_instance_t;
 typedef struct _dc_backup_provider dc_backup_provider_t;
+typedef struct _dc_http_response dc_http_response_t;
 
 // Alias for backwards compatibility, use dc_event_emitter_t instead.
 typedef struct _dc_event_emitter dc_accounts_event_emitter_t;
@@ -5057,6 +5058,63 @@ int             dc_provider_get_status                (const dc_provider_t* prov
 void            dc_provider_unref                     (dc_provider_t* provider);
 
 
+/**
+ * Return an HTTP(S) GET response.
+ * This function can be used to download remote content for HTML emails.
+ *
+ * @memberof dc_context_t
+ * @param context The context object to take proxy settings from.
+ * @param url HTTP or HTTPS URL.
+ * @return The response must be released using dc_http_response_unref() after usage.
+ *     NULL is returned on errors.
+ */
+dc_http_response_t*     dc_get_http_response      (const dc_context_t* context, const char* url);
+
+/**
+ * Returns HTTP response MIME type as a string, e.g. "text/plain" or "text/html".
+ *
+ * @memberof dc_http_response_t
+ * @param response HTTP response as returned by dc_get_http_response().
+ * @return The string which must be released using dc_str_unref() after usage. May be NULL.
+ */
+char*                   dc_http_response_get_mimetype (const dc_http_response_t* response);
+
+/**
+ * Returns HTTP response encoding, e.g. "utf-8".
+ *
+ * @memberof dc_http_response_t
+ * @param response HTTP response as returned by dc_get_http_response().
+ * @return The string which must be released using dc_str_unref() after usage. May be NULL.
+ */
+char*                   dc_http_response_get_encoding (const dc_http_response_t* response);
+
+/**
+ * Returns HTTP response contents.
+ *
+ * @memberof dc_http_response_t
+ * @param response HTTP response as returned by dc_get_http_response().
+ * @return The blob which must be released using dc_str_unref() after usage. NULL is never returned.
+ */
+uint8_t*                dc_http_response_get_blob     (const dc_http_response_t* response);
+
+/**
+ * Returns HTTP response content size.
+ *
+ * @memberof dc_http_response_t
+ * @param response HTTP response as returned by dc_get_http_response().
+ * @return The blob size.
+ */
+size_t                  dc_http_response_get_size     (const dc_http_response_t* response);
+
+/**
+ * Free an HTTP response object.
+ *
+ * @memberof dc_http_response_t
+ * @param response HTTP response as returned by dc_get_http_response().
+ */
+void                    dc_http_response_unref        (const dc_http_response_t* response);
+
+
 /**
  * @class dc_lot_t
  *
@@ -5534,7 +5592,6 @@ void            dc_reactions_unref       (dc_reactions_t* reactions);
  */
 
 
-
 /**
  * @class dc_jsonrpc_instance_t
  *

deltachat-ffi/src/lib.rs

@@ -31,6 +31,7 @@ use deltachat::ephemeral::Timer as EphemeralTimer;
 use deltachat::imex::BackupProvider;
 use deltachat::key::DcKey;
 use deltachat::message::MsgId;
+use deltachat::net::read_url_blob;
 use deltachat::qr_code_generator::{generate_backup_qr, get_securejoin_qr_svg};
 use deltachat::reaction::{get_msg_reactions, send_reaction, Reactions};
 use deltachat::stock_str::StockMessage;
@@ -4467,6 +4468,93 @@ pub unsafe extern "C" fn dc_provider_unref(provider: *mut dc_provider_t) {
     // this may change once we start localizing string.
 }
 
+// dc_http_response_t
+
+pub type dc_http_response_t = net::HttpResponse;
+
+#[no_mangle]
+pub unsafe extern "C" fn dc_get_http_response(
+    context: *const dc_context_t,
+    url: *const libc::c_char,
+) -> *mut dc_http_response_t {
+    if context.is_null() || url.is_null() {
+        eprintln!("ignoring careless call to dc_get_http_response()");
+        return ptr::null_mut();
+    }
+
+    let context = &*context;
+    let url = to_string_lossy(url);
+    if let Ok(response) = block_on(read_url_blob(context, &url)).log_err(context, "read_url_blob") {
+        Box::into_raw(Box::new(response))
+    } else {
+        ptr::null_mut()
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn dc_http_response_get_mimetype(
+    response: *const dc_http_response_t,
+) -> *mut libc::c_char {
+    if response.is_null() {
+        eprintln!("ignoring careless call to dc_http_response_get_mimetype()");
+        return ptr::null_mut();
+    }
+
+    let response = &*response;
+    response.mimetype.strdup()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn dc_http_response_get_encoding(
+    response: *const dc_http_response_t,
+) -> *mut libc::c_char {
+    if response.is_null() {
+        eprintln!("ignoring careless call to dc_http_response_get_encoding()");
+        return ptr::null_mut();
+    }
+
+    let response = &*response;
+    response.encoding.strdup()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn dc_http_response_get_blob(
+    response: *const dc_http_response_t,
+) -> *mut libc::c_char {
+    if response.is_null() {
+        eprintln!("ignoring careless call to dc_http_response_get_blob()");
+        return ptr::null_mut();
+    }
+
+    let response = &*response;
+    let blob_len = response.blob.len();
+    let ptr = libc::malloc(blob_len);
+    libc::memcpy(ptr, response.blob.as_ptr() as *mut libc::c_void, blob_len);
+    ptr as *mut libc::c_char
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn dc_http_response_get_size(
+    response: *const dc_http_response_t,
+) -> libc::size_t {
+    if response.is_null() {
+        eprintln!("ignoring careless call to dc_http_response_get_size()");
+        return 0;
+    }
+
+    let response = &*response;
+    response.blob.len()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn dc_http_response_unref(response: *mut dc_http_response_t) {
+    if response.is_null() {
+        eprintln!("ignoring careless call to dc_http_response_unref()");
+        return;
+    }
+    drop(Box::from_raw(response));
+}
+
 // -- Accounts
 
 /// Reader-writer lock wrapper for accounts manager to guarantee thread safety when using