.

wcfs/internal/wcfs.h

@@ -109,9 +109,8 @@ public:
     void decref();
 
 public:
+    pair<FileH, error> open(zodb::Oid foid);
     error close();
-    // XXX move mmap -> FileH
-    pair<Mapping, error> mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len);
     error resync(zodb::Tid at);
 
 private:
@@ -140,10 +139,12 @@ struct _FileH : object {
 private:
     _FileH();
     ~_FileH();
-    // XXX -> friend Conn::open
-    friend pair<Mapping, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len);
+    friend pair<FileH, error> _Conn::open(zodb::Oid foid);
 public:
     void decref();
+
+public:
+    pair<Mapping, error> mmap(int64_t blk_start, int64_t blk_len);
 };
 
 // Mapping represents one mapping of FileH.
@@ -170,14 +171,12 @@ struct _Mapping : object {
 private:
     _Mapping();
     ~_Mapping();
-    // XXX -> friend FileH.mmap
-    friend pair<Mapping, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len);
+    friend pair<Mapping, error> _FileH::mmap(int64_t blk_start, int64_t blk_len);
 public:
     void decref();
 };
 
 
-
 }   // wcfs::
 
 #endif

wcfs/internal/wcfs_virtmem.cpp

@@ -235,19 +235,11 @@ void _Conn::_pin1(PinReq *req) {
     wconn._filehmu.unlock();
 }
 
-// mmap creates file mapping representing file[blk_start +blk_len) data as of wconn.at database state.
-pair<Mapping, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_len) {
+// open opens FileH corresponding to ZBigFile foid.
+pair<FileH, error> _Conn::open(zodb::Oid foid) {
     _Conn& wconn = *this;
-    // XXX err ctx
-    // XXX (blk_start + blk_len) * blk_size overflow
     error err;
-
-    if (blk_start < 0)
-        panic("blk_start < 0");
-    if (blk_len < 0)
-        panic("blk_len < 0");
-
-    int64_t blk_stop = blk_start + blk_len;     // XXX overflow
+    // XXX err ctx
 
     wconn._filehmu.lock();
     defer([&]() {
@@ -257,6 +249,12 @@ pair<Mapping, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_
     FileH f; bool ok;
     tie(f, ok) = wconn._filehtab.get(foid);
     if (f == nil) {
+        // XXX incref open count?
+        return make_pair(f, nil);
+    }
+
+    // TODO perform open with filehmu released
+
     f = adoptref(new _FileH());
     f->wconn    = newref(&wconn);    // XXX newref -> simpler?
     f->_foid    = foid;
@@ -264,8 +262,6 @@ pair<Mapping, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_
                 = wconn._wc->_open(fmt::sprintf("head/bigfile/%s", h_(foid)));
     if (err != nil)
         return make_pair(nil, err);
-        //f._pinned   = {}
-        //f._mmaps    = []
 
     struct stat st;
     err = f->_headf->stat(&st);
@@ -286,36 +282,52 @@ pair<Mapping, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_
     if (ack != "ok") {
         // XXX unregister f from _filehtab
         // XXX vvv -> errctx?
-            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()));
-        }
+        return make_pair(nil, fmt::errorf("@%s: open f<%s>: watch: %s", h_(wconn.at), h_(foid), ack.c_str()));
     }
 
-    // XXX relock wconn -> f ?
+    return make_pair(f, nil);
+}
+
+// mmap creates file mapping representing file[blk_start +blk_len) data as of wconn.at database state.
+pair<Mapping, error> _FileH::mmap(int64_t blk_start, int64_t blk_len) {
+    _FileH& f = *this;
+    // XXX err ctx
+    // XXX (blk_start + blk_len) * blk_size overflow
+    error err;
+
+    if (blk_start < 0)
+        panic("blk_start < 0");
+    if (blk_len < 0)
+        panic("blk_len < 0");
+
+    int64_t blk_stop = blk_start + blk_len;     // XXX overflow
+
+    // XXX f locking?
 
     // create memory with head/f mapping and applied pins
     // mmap-in zeros after f.size (else access to memory after file.size will raise SIGBUS)
-    int64_t start = blk_start*f->_blksize;
+    int64_t start = blk_start*f._blksize;
     uint8_t *mem_start, *mem_stop;
-    tie(mem_start, err) = mmap_ro(f->_headf, start, blk_len*f->_blksize);
+    tie(mem_start, err) = mmap_ro(f._headf, start, blk_len*f._blksize);
     if (err != nil)
         return make_pair(nil, err);
-    mem_stop = mem_start + blk_len*f->_blksize;
+    mem_stop = mem_start + blk_len*f._blksize;
 
-    int64_t stop = blk_stop*f->_blksize;
-    if (stop > f->_headfsize) {
-        uint8_t *zmem_start = mem_start + (max(f->_headfsize/*XXX -1 ?*/, start) - start);
+    int64_t stop = blk_stop*f._blksize;
+    if (stop > f._headfsize) {
+        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)
             return make_pair(nil, err);
     }
 
     Mapping mmap = adoptref(new _Mapping());
-    mmap->fileh     = f;
+    mmap->fileh     = newref(&f);   // XXX newref - simpler?
     mmap->blk_start = blk_start;
     mmap->mem_start = mem_start;
     mmap->mem_stop  = mem_stop;
 
-    for (auto _ : f->_pinned) {  // XXX keep f._pinned ↑blk and use binary search?
+    for (auto _ : f._pinned) {  // XXX keep f._pinned ↑blk and use binary search?
         int64_t    blk = _.first;
         zodb::Tid  rev = _.second;
         if (!(blk_start <= blk && blk < blk_stop))
@@ -323,7 +335,7 @@ pair<Mapping, error> _Conn::mmap(zodb::Oid foid, int64_t blk_start, int64_t blk_
         mmap->_remmapblk(blk, rev); // XXX err?
     }
 
-    f->_mmaps.push_back(mmap);    // XXX keep f._mmaps ↑blk_start
+    f._mmaps.push_back(mmap);    // XXX keep f._mmaps ↑blk_start
 
     return make_pair(mmap, nil);
 }