feat: add delete; update examples

easystorage.c

@@ -9,7 +9,7 @@
 #include <string.h>
 #include <unistd.h>
 
-#define MAX_RETRIES 250
+#define MAX_RETRIES 1000
 #define POLL_INTERVAL_US (100 * 1000)
 #define DEFAULT_CHUNK_SIZE (64 * 1024)
 
@@ -45,10 +45,12 @@ static void resp_destroy(resp *r) {
     free(r);
 }
 
-static void resp_wait(resp *r) {
-    for (int i = 0; i < MAX_RETRIES && r->ret == -1; i++) {
+static bool resp_wait(resp *r) {
+    int i;
+    for (i = 0; i < MAX_RETRIES && r->ret == -1; i++) {
         usleep(POLL_INTERVAL_US);
     }
+    return i == MAX_RETRIES;
 }
 
 // Callback for simple (non-progress) async operations.
@@ -119,13 +121,18 @@ static void on_progress(int ret, const char *msg, size_t len, void *userData) {
 // Returns RET_OK/RET_ERR. If dispatch_ret != RET_OK, returns RET_ERR immediately.
 // If **out is non-NULL, allocates a buffer and copies the content of
 // resp->msg onto it, which the caller must then free.
+// Manages deallocation of resp such that it only gets deallocated after both
+// this call returns AND the callback has run. Will leak memory if the call
+// succeeds but the callback then fails to run.
 static int call_wait(int dispatch_ret, resp *r, char **out) {
     if (dispatch_ret != RET_OK) {
         resp_destroy(r);
         return RET_ERR;
     }
 
-    resp_wait(r);
+    if (resp_wait(r)) {
+        fprintf(stderr, "CRITICAL: Call timed out!");
+    }
 
     pthread_mutex_lock(&mutex);
     int result = (r->ret == RET_OK) ? RET_OK : RET_ERR;
@@ -294,6 +301,18 @@ int e_storage_download(STORAGE_NODE node, const char *cid, const char *filepath,
     return ret;
 }
 
+int e_storage_delete(STORAGE_NODE node, const char *cid) {
+    if (!node || !cid) return RET_ERR;
+
+    resp *r = resp_alloc();
+    int ret = call_wait(storage_delete(node, cid, on_complete, r), r, NULL);
+    if (ret != RET_OK) {
+        return RET_ERR;
+    }
+
+    return ret;
+}
+
 static int handler(void *user, const char *section, const char *name, const char *value) {
     node_config *cfg = (node_config *) user;
 #define MATCH(n) strcmp(section, "easystorage") == 0 && strcmp(name, n) == 0

easystorage.h

@@ -4,6 +4,8 @@
 #include <stdio.h>
 
 #define STORAGE_NODE void *
+#define RET_OK 0
+#define RET_ERR 1
 
 typedef struct {
     int api_port;
@@ -34,6 +36,9 @@ char *e_storage_upload(STORAGE_NODE node, const char *filepath, progress_callbac
 // Downloads content identified by cid to filepath. Returns 0 on success.
 int e_storage_download(STORAGE_NODE node, const char *cid, const char *filepath, progress_callback cb);
 
+// Deletes a previously uploaded file from the node.
+int e_storage_delete(STORAGE_NODE node, const char *cid);
+
 // Config handling utilities. Note that for e_storage_read_config and e_storage_read_config, the
 // caller is responsible for freeing the config object and its members.
 int e_storage_read_config(char *filepath, node_config *config);

examples/downloader.c

@@ -4,6 +4,11 @@
 #include <stdlib.h>
 #include "easystorage.h"
 
+void panic(const char *msg) {
+    fprintf(stderr, "Panic: %s\n", msg);
+    exit(1);
+}
+
 void progress(int total, int complete, int status) {
     printf("\r  %d / %d bytes", complete, total);
     fflush(stdout);
@@ -29,8 +34,8 @@ int main(int argc, char *argv[]) {
     };
 
     STORAGE_NODE node = e_storage_new(cfg);
-    e_storage_start(node);
-    e_storage_download(node, cid, filepath, progress);
+    if (e_storage_start(node) != RET_OK) panic("Failed to start storage node");
+    if (e_storage_download(node, cid, filepath, progress) != RET_OK) panic("Failed to download file");
     e_storage_stop(node);
     e_storage_destroy(node);
 }

examples/uploader.c

@@ -4,6 +4,11 @@
 #include <stdlib.h>
 #include "easystorage.h"
 
+void panic(const char *msg) {
+    fprintf(stderr, "Panic: %s\n", msg);
+    exit(1);
+}
+
 void progress(int total, int complete, int status) {
     printf("\r  %d / %d bytes", complete, total);
     fflush(stdout);
@@ -27,18 +32,25 @@ int main(int argc, char *argv[]) {
     char *filepath = argv[1];
 
     STORAGE_NODE node = e_storage_new(cfg);
-    e_storage_start(node);
+    if (node == NULL) panic("Failed to create node");
+    if (e_storage_start(node) != RET_OK) panic("Failed to start storage node");
 
     char *cid = e_storage_upload(node, filepath, progress);
+    if (cid == NULL) panic("Failed to upload file to node");
     char *spr = e_storage_spr(node);
+    if (spr == NULL) panic("Failed to obtain node's Signed Peer Record (SPR)");
 
     printf("Run: downloader %s %s ./output-file\n", spr, cid);
-    free(cid);
-    free(spr);
-
     printf("\nPress Enter to exit\n");
     getchar();
 
+    printf("Deleting file (this could take a while)...");
+    fflush(stdout);
+    if (e_storage_delete(node, cid) != RET_OK) panic("Failed to delete file");
+    printf("Done\n");
+
+    free(cid);
+    free(spr);
     e_storage_stop(node);
     e_storage_destroy(node);
 

tests/mock_libstorage.c

@@ -3,8 +3,11 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define FAKE_CID "zDvZRwzmAbCdEfGhIjKlMnOpQrStUvWxYz0123456789ABCD"
+
 // A fake context to return from storage_new.
 static int fake_ctx_data = 42;
+bool exists = false;
 
 void libstorageNimMain(void) {
     // no-op
@@ -70,12 +73,29 @@ int storage_upload_file(void *ctx, const char *sessionId, StorageCallback callba
     // Fire a progress callback first, then final OK with CID
     if (callback) {
         callback(RET_PROGRESS, "chunk", 5, userData);
-        const char *cid = "zDvZRwzmAbCdEfGhIjKlMnOpQrStUvWxYz0123456789ABCD";
+        const char *cid = FAKE_CID;
         callback(RET_OK, cid, strlen(cid), userData);
+        exists = true;
     }
     return RET_OK;
 }
 
+int storage_delete(void *ctx, const char *cid, StorageCallback callback, void *userData) {
+    if (!ctx)
+        return RET_ERR;
+
+    if (callback) {
+        if (strcmp(cid, FAKE_CID) == 0 && exists) {
+            callback(RET_OK, "", 0, userData);
+            exists = false;
+        } else {
+            callback(RET_ERR, "Failed", 6, userData);
+        }
+    }
+
+    return RET_OK;
+}
+
 int storage_download_init(void *ctx, const char *cid, size_t chunkSize, bool local, StorageCallback callback,
                           void *userData) {
     if (!ctx)

tests/test_runner.c

@@ -122,6 +122,22 @@ static void test_download_null(void) {
     assert(ret == RET_ERR);
 }
 
+static void test_should_delete_file(void) {
+    node_config cfg = default_config();
+    STORAGE_NODE node = e_storage_new(cfg);
+    assert(node != NULL);
+    e_storage_start(node);
+
+    char *cid = e_storage_upload(node, "/tmp/test.txt", NULL);
+    assert(cid != NULL);
+    assert(strlen(cid) > 0);
+
+    assert(e_storage_delete(node, cid) == RET_OK);
+    // Non-existing files can't be deleted.
+    assert(e_storage_delete(node, cid) == RET_ERR);
+    free(cid);
+}
+
 static void test_get_should_get_node_spr(void) {
     node_config cfg = default_config();
     STORAGE_NODE node = e_storage_new(cfg);
@@ -193,6 +209,7 @@ int main(void) {
     RUN_TEST(test_upload_null);
     RUN_TEST(test_download);
     RUN_TEST(test_download_null);
+    RUN_TEST(test_should_delete_file);
     RUN_TEST(test_get_should_get_node_spr);
     RUN_TEST(test_full_lifecycle);
     RUN_TEST(test_should_read_configuration_file);