From bc23ee03a232e11bad2240a55d0d6088cbaff051 Mon Sep 17 00:00:00 2001
From: Fufu Fang <fangfufu2003@gmail.com>
Date: Wed, 4 Sep 2019 19:53:11 +0100
Subject: [PATCH] Fixed regression: LinkTable caching now works again.

---
 src/cache.c |  7 +------
 src/cache.h |  5 +++++
 src/link.c  | 49 +++++++++++++++++++++++++++++++++++++------------
 3 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/src/cache.c b/src/cache.c
index 5a42d0c..502c22c 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -40,6 +40,7 @@ typedef enum {
 int CACHE_SYSTEM_INIT = 0;
 int DATA_BLK_SZ = 0;
 int MAX_SEGBC = DEFAULT_MAX_SEGBC;
+char *META_DIR;
 
 /* ----------------- Static variables ----------------------- */
 
@@ -49,12 +50,6 @@ int MAX_SEGBC = DEFAULT_MAX_SEGBC;
  */
 static pthread_mutex_t cf_lock;
 
-
-/**
- * \brief The metadata directory
- */
-static char *META_DIR;
-
 /**
  * \brief The data directory
  */
diff --git a/src/cache.h b/src/cache.h
index e30c227..0a4e004 100644
--- a/src/cache.h
+++ b/src/cache.h
@@ -80,6 +80,11 @@ extern int DATA_BLK_SZ;
  */
 extern int MAX_SEGBC;
 
+/**
+ * \brief The metadata directory
+ */
+extern char *META_DIR;
+
 /**
  * \brief initialise the cache system directories
  * \details This function basically sets up the following variables:
diff --git a/src/link.c b/src/link.c
index cdc20b1..1dd0f32 100644
--- a/src/link.c
+++ b/src/link.c
@@ -266,16 +266,19 @@ static void LinkTable_fill(LinkTable *linktbl)
 }
 
 /**
- * \brief fill in the gaps in a link table
+ * \brief Reset invalid links in the link table
  */
 static void LinkTable_invalid_reset(LinkTable *linktbl)
 {
+    int j = 0;
     for (int i = 0; i < linktbl->num; i++) {
         Link *this_link = linktbl->links[i];
         if (this_link->type == LINK_INVALID) {
             this_link->type = LINK_UNINITIALISED_FILE;
+            j++;
         }
     }
+    fprintf(stderr, "LinkTable_invalid_reset(): %d invalid links\n", j);
 }
 
 static void LinkTable_free(LinkTable *linktbl)
@@ -348,12 +351,14 @@ LinkTable *LinkTable_new(const char *url)
         transfer_blocking(curl);
         curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_resp);
         if (HTTP_temp_failure(http_resp)) {
-            fprintf(stderr, "LinkTable_new(): URL: %s, HTTP %ld, \
-retrying later.\n", url, http_resp);
+            fprintf(stderr,
+                    "LinkTable_new(): URL: %s, HTTP %ld, retrying later.\n",
+                    url, http_resp);
             sleep(HTTP_WAIT_SEC);
         } else if (http_resp != HTTP_OK) {
-            fprintf(stderr, "LinkTable_new(): cannot retrieve URL: %s, \
-HTTP %ld\n", url, http_resp);
+            fprintf(stderr,
+                    "LinkTable_new(): cannot retrieve URL: %s, HTTP %ld\n",
+                    url, http_resp);
             LinkTable_free(linktbl);
             curl_easy_cleanup(curl);
             return NULL;
@@ -380,6 +385,9 @@ HTTP %ld\n", url, http_resp);
         disk_linktbl = LinkTable_disk_open(unescaped_path);
         if (disk_linktbl) {
             /* Check if we need to update the link table */
+            fprintf(stderr,
+                "LinkTable_new(): disk_linktbl->num: %d, linktbl->num: %d\n",
+                disk_linktbl->num, linktbl->num);
             if (disk_linktbl->num == linktbl->num) {
                 LinkTable_free(linktbl);
                 linktbl = disk_linktbl;
@@ -401,7 +409,9 @@ HTTP %ld\n", url, http_resp);
 
     /* Save the link table */
     if (CACHE_SYSTEM_INIT) {
-        LinkTable_disk_save(linktbl, unescaped_path);
+        if (LinkTable_disk_save(linktbl, unescaped_path)) {
+            exit_failure();
+        }
     }
 
     curl_free(unescaped_path);
@@ -419,8 +429,13 @@ HTTP %ld\n", url, http_resp);
 
 static void LinkTable_disk_delete(const char *dirn)
 {
-    char *metadirn = path_append("cache/meta/", dirn);
-    char *path = path_append(metadirn, ".LinkTable");
+    char *metadirn = path_append(META_DIR, dirn);
+    char *path;
+    if (metadirn[strnlen(metadirn, MAX_PATH_LEN)] == '/') {
+        path = path_append(metadirn, ".LinkTable");
+    } else {
+        path = path_append(metadirn, "/.LinkTable");
+    }
     if(unlink(path)) {
         fprintf(stderr, "LinkTable_disk_delete(): unlink(%s): %s\n", path,
                 strerror(errno));
@@ -431,8 +446,13 @@ static void LinkTable_disk_delete(const char *dirn)
 
 int LinkTable_disk_save(LinkTable *linktbl, const char *dirn)
 {
-    char *metadirn = path_append("cache/meta/", dirn);
-    char *path = path_append(metadirn, ".LinkTable");
+    char *metadirn = path_append(META_DIR, dirn);
+    char *path;
+    if (metadirn[strnlen(metadirn, MAX_PATH_LEN)] == '/') {
+        path = path_append(metadirn, ".LinkTable");
+    } else {
+        path = path_append(metadirn, "/.LinkTable");
+    }
     FILE *fp = fopen(path, "w");
     free(metadirn);
 
@@ -472,8 +492,13 @@ int LinkTable_disk_save(LinkTable *linktbl, const char *dirn)
 
 LinkTable *LinkTable_disk_open(const char *dirn)
 {
-    char *metadirn = path_append("cache/meta/", dirn);
-    char *path = path_append(metadirn, ".LinkTable");
+    char *metadirn = path_append(META_DIR, dirn);
+    char *path;
+    if (metadirn[strnlen(metadirn, MAX_PATH_LEN)] == '/') {
+        path = path_append(metadirn, ".LinkTable");
+    } else {
+        path = path_append(metadirn, "/.LinkTable");
+    }
     FILE *fp = fopen(path, "r");
     free(metadirn);