Update networking layer w/ CURL and emscripten impl

2025-11-08 01:50:36 +11:00
parent a17925904d
commit f6874dc55a
4105 changed files with 694617 additions and 179 deletions
@@ -0,0 +1,126 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLOPT_XFERINFOFUNCTION
+Section: 3
+Source: libcurl
+See-also:
+  - CURLOPT_NOPROGRESS (3)
+  - CURLOPT_XFERINFODATA (3)
+Protocol:
+  - All
+Added-in: 7.32.0
+---
+
+# NAME
+
+CURLOPT_XFERINFOFUNCTION - progress meter callback
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+int progress_callback(void *clientp,
+                      curl_off_t dltotal,
+                      curl_off_t dlnow,
+                      curl_off_t ultotal,
+                      curl_off_t ulnow);
+
+CURLcode curl_easy_setopt(CURL *handle, CURLOPT_XFERINFOFUNCTION,
+                          progress_callback);
+~~~
+
+# DESCRIPTION
+
+Pass a pointer to your callback function, which should match the prototype
+shown above.
+
+This function gets called by libcurl instead of its internal equivalent with a
+frequent interval. While data is being transferred it gets called frequently,
+and during slow periods like when nothing is being transferred it can slow
+down to about one call per second.
+
+*clientp* is the pointer set with CURLOPT_XFERINFODATA(3), it is not
+used by libcurl but is only passed along from the application to the callback.
+
+The callback gets told how much data libcurl is about to transfer and has
+already transferred, in number of bytes. *dltotal* is the total number of
+bytes libcurl expects to download in this transfer. *dlnow* is the number
+of bytes downloaded so far. *ultotal* is the total number of bytes libcurl
+expects to upload in this transfer. *ulnow* is the number of bytes
+uploaded so far.
+
+Unknown/unused argument values passed to the callback are set to zero (like if
+you only download data, the upload size remains 0). Many times the callback is
+called one or more times first, before it knows the data sizes so a program
+must be made to handle that.
+
+Return zero from the callback if everything is fine.
+
+Return 1 from this callback to make libcurl abort the transfer and return
+*CURLE_ABORTED_BY_CALLBACK*.
+
+If your callback function returns CURL_PROGRESSFUNC_CONTINUE it makes libcurl
+to continue executing the default progress function.
+
+If you transfer data with the multi interface, this function is not called
+during periods of idleness unless you call the appropriate libcurl function
+that performs transfers.
+
+CURLOPT_NOPROGRESS(3) must be set to 0 to make this function actually
+get called.
+
+# DEFAULT
+
+NULL - use the internal progress meter. That is rarely wanted by users.
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+struct progress {
+  char *private;
+  size_t size;
+};
+
+static int xferinfo_callback(void *clientp,
+                             curl_off_t dltotal,
+                             curl_off_t dlnow,
+                             curl_off_t ultotal,
+                             curl_off_t ulnow)
+{
+  struct progress *memory = clientp;
+  printf("my ptr: %p\n", memory->private);
+
+  /* use the values */
+
+  return 0; /* all is good */
+}
+
+int main(void)
+{
+  CURL *curl = curl_easy_init();
+  if(curl) {
+    struct progress data;
+
+    /* pass struct to callback  */
+    curl_easy_setopt(curl, CURLOPT_XFERINFODATA, &data);
+
+    /* enable progress callback getting called */
+    curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
+
+    curl_easy_setopt(curl, CURLOPT_XFERINFOFUNCTION, xferinfo_callback);
+  }
+}
+~~~
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+curl_easy_setopt(3) returns a CURLcode indicating success or error.
+
+CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
+libcurl-errors(3).