.

wcfs/internal/wcfs.h

@@ -92,7 +92,7 @@ public:
 
 public:
     error close();
-    _Mapping* mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len);
+    pair<_Mapping*, error> mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len);
     error resync(zodb::Tid at);
 
 private:

wcfs/internal/wcfs_virtmem.cpp

@@ -254,7 +254,7 @@ void _Conn::_pin1(PinReq *req) {
 }
 
 // mmap creates file mapping representing file[blk_start +blk_len) data as of wconn.at database state.
-_Mapping* _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
+pair<_Mapping*, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
     _Conn& wconn = *this;
     // XXX err ctx
     // XXX (blk_start + blk_len) * blk_size overflow
@@ -275,25 +275,24 @@ _Mapping* _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
     _File* f; bool ok;
     tie(f, ok) = wconn._filetab.get(foid);
     if (f == nil) {
-        f = new _File();
+        f = new _File();    // XXX free f on error return (will be automatic if f = refptr)
         f->wconn    = newref(&wconn);    // XXX newref -> simpler?
         f->foid     = foid;
         tie(f->headf, err)
                     = wconn._wc->_open(fmt::sprintf("head/bigfile/%s", h_(foid)));
         if (err != nil)
-            panic("TODO");  // XXX err
+            return make_pair(nil, err);
         //f.pinned    = {}
         //f.mmaps     = []
 
         struct stat st;
         err = f->headf->stat(&st);
         if (err != nil)
-            panic("TODO");  // XXX
+            return make_pair(nil, err);
         f->blksize   = st.st_blksize;
         f->headfsize = st.st_size;
         if (!(f->headfsize % f->blksize == 0))
-            //return fmt::errorf("wcfs bug: head/file size %% blksize != 0");
-            panic("wcfs bug: head/file size %% blksize != 0"); // XXX -> err
+            return make_pair(nil, fmt::errorf("wcfs bug: head/file size %% blksize != 0"));
 
         wconn._filetab[foid] = f;
 
@@ -301,12 +300,11 @@ _Mapping* _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
         string ack;
         tie(ack, err) = wconn._wlink->sendReq(context::background(), fmt::sprintf("watch %s @%s", h_(foid), h_(wconn.at)));
         if (err != nil)
-            panic("TODO");  // XXX
+            return make_pair(nil, err);
         if (ack != "ok") {
             // XXX unregister f from _filetab
             // XXX vvv -> errctx?
-            /*return XXX*/ fmt::errorf("@%s: mmap f<%s>[%zd +%zd): %s", h_(wconn.at), h_(foid), blk_start, blk_len, ack.c_str());
-            panic("TODO ack != ok");    // XXX ^^^
+            return make_pair(nil, fmt::errorf("@%s: mmap f<%s>[%zd +%zd): %s", h_(wconn.at), h_(foid), blk_start, blk_len, ack.c_str()));
         }
     }
 
@@ -318,7 +316,7 @@ _Mapping* _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
     uint8_t *mem_start, *mem_stop;
     tie(mem_start, err) = mmap_ro(f->headf, start, blk_len*f->blksize);
     if (err != nil)
-        panic("TODO");  // XXX
+        return make_pair(nil, err);
     mem_stop = mem_start + blk_len*f->blksize;
 
     int64_t stop = blk_stop*f->blksize;
@@ -326,7 +324,7 @@ _Mapping* _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
         uint8_t *zmem_start = mem_start + (max(f->headfsize/*XXX -1 ?*/, start) - start);
         err = mmap_zero_into_ro(zmem_start, mem_stop - zmem_start);
         if (err != nil)
-            panic("TODO");  // XXX
+            return make_pair(nil, err);
     }
 
     _Mapping* mmap = new _Mapping();
@@ -345,7 +343,7 @@ _Mapping* _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
 
     f->mmaps.push_back(mmap);    // XXX keep f.mmaps ↑blk_start
 
-    return mmap;
+    return make_pair(mmap, nil);
 }
 
 // resync resyncs connection and its mappings onto different database view.