1 files changed, 177 insertions, 0 deletions
diff --git a/src/downloadpool.c b/src/downloadpool.c
new file mode 100644
index 0000000..5da2905
--- /dev/null
+++ b/src/downloadpool.c
@@ -0,0 +1,177 @@
+#include "downloadpool.h"
+#include "macros.h"
+#include <curl/curl.h>
+#include <curl/multi.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+struct l2_dlpool__handle {
+  CURL *easy;
+  void *user;
+
+  struct l2_dlpool__handle *next;
+  struct l2_dlpool__handle *prev;
+};
+
+struct l2_dlpool__pool_tag {
+  CURLM *multi;
+
+  struct l2_dlpool__handle *head, *tail;
+  
+  l2_dlpool_download_init_proc_t *initproc;
+  l2_dlpool_one_downloaded_proc_t *dlproc;
+};
+
+l2_dlpool_t *l2_dlpool_init(l2_dlpool_download_init_proc_t *init, l2_dlpool_one_downloaded_proc_t *dlproc)
+{
+  l2_dlpool_t *ret = calloc(1, sizeof(l2_dlpool_t));
+  if (!ret) return NULL;
+
+  ret->multi = curl_multi_init();
+  if (!ret->multi) {
+    goto cleanup;
+  }
+
+  ret->initproc = init;
+  ret->dlproc = dlproc;
+
+  return ret;
+
+cleanup:
+  if (ret) {
+    if (ret->multi) curl_multi_cleanup(ret->multi);
+  }
+  free(ret);
+  return NULL;
+}
+
+int l2_dlpool_add(l2_dlpool_t *pool, void *user)
+{
+  int res = -1;
+  struct l2_dlpool__handle *newhandle = calloc(1, sizeof(struct l2_dlpool__handle));
+  if (!newhandle) return -1;
+
+  newhandle->easy = curl_easy_init();
+  if (!newhandle->easy) goto cleanup;
+
+  curl_easy_setopt(newhandle->easy, CURLOPT_USERAGENT, L2_USER_AGENT);
+
+  if ((*pool->initproc)(newhandle->easy, user) < 0) {
+    res = 0;
+    goto cleanup;
+  }
+
+  newhandle->user = user;
+
+  CURLMcode mc = curl_multi_add_handle(pool->multi, newhandle->easy);
+  if (mc != CURLM_OK) {
+    if (mc == CURLM_OUT_OF_MEMORY) {
+      fputs("CURL out of memory. (You are doomed.)\n", stderr);
+      abort();
+    }
+    goto cleanup;
+  }
+
+  if (pool->tail) {
+    pool->tail->next = newhandle;
+    newhandle->prev = pool->tail;
+    pool->tail = newhandle;
+  } else {
+    pool->head = pool->tail = newhandle;
+  }
+
+  return 1;
+
+cleanup:
+  if (newhandle) {
+    if (newhandle->easy) curl_easy_cleanup(newhandle->easy);
+  }
+  free(newhandle);
+  return res;
+}
+
+int l2_dlpool__download_complete(l2_dlpool_t *pool, CURL *easy, CURLcode code)
+{
+  struct l2_dlpool__handle *handle = NULL;
+  int uret = 0;
+  for (struct l2_dlpool__handle *cur = pool->head; cur; cur = cur->next) {
+    if (cur->easy == easy) {
+      handle = cur;
+      continue;
+    }
+  }
+
+  if (handle) {
+    uret = (*pool->dlproc)(easy, code, handle->user);
+
+    if (handle->prev) {
+      handle->prev->next = handle->next;
+    } else {
+      pool->head = handle->next;
+    }
+
+    if (handle->next) {
+      handle->next->prev = handle->prev;
+    } else {
+      pool->tail = handle->prev;
+    }
+
+    free(handle);
+    handle = NULL;
+  }
+
+  curl_multi_remove_handle(pool->multi, easy);
+  curl_easy_cleanup(easy);
+
+  if (uret < 0) return -1;
+  return 0;
+}
+
+int l2_dlpool_perform(l2_dlpool_t *pool)
+{
+  CURLMcode code;
+  int running = 0;
+  int queuelen = 0;
+  CURLMsg *msg;
+
+  do {
+    code = curl_multi_perform(pool->multi, &running);
+    if (code != CURLM_OK) {
+      return -1;
+    }
+
+    while ((msg = curl_multi_info_read(pool->multi, &queuelen))) {
+      if (msg->msg == CURLMSG_DONE) {
+        if (l2_dlpool__download_complete(pool, msg->easy_handle, msg->data.result) < 0) return -1;
+      }
+    }
+
+    code = curl_multi_poll(pool->multi, NULL, 0, 1000, NULL);
+    if (code != CURLM_OK) {
+      return -1;
+    }
+  } while (running);
+
+  return 0;
+}
+
+void l2_dlpool_cleanup(l2_dlpool_t *pool)
+{
+  if (!pool) return;
+
+  /* assumes pool->multi is valid (API must not return a handle where this isn't the case) */
+
+  /* curl docs say to remove handles BEFORE ANY HANDLES ARE CLEANED UP */
+  for (struct l2_dlpool__handle *cur = pool->head; cur; cur = cur->next) {
+    curl_multi_remove_handle(pool->multi, cur->easy); /* assume it succeeds (if it fails, too bad we tried LOL) */
+  }
+
+  for (struct l2_dlpool__handle *cur = pool->head, *temp; cur; cur = temp) {
+    temp = cur->next;
+    curl_easy_cleanup(cur->easy);
+    free(cur);
+  }
+
+  curl_multi_cleanup(pool->multi);
+  free(pool);
+}