From 224c585aba5e450fa47e41c4cc19dac2d0c6fe2a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <e.dolstra@tudelft.nl>
Date: Mon, 7 Jul 2003 07:43:58 +0000
Subject: * Refactoring on the file names.

---
 src/store.cc | 132 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 src/store.cc

(limited to 'src/store.cc')

diff --git a/src/store.cc b/src/store.cc
new file mode 100644
index 000000000000..68a1cd1e2879
--- /dev/null
+++ b/src/store.cc
@@ -0,0 +1,132 @@
+#include <iostream>
+
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "store.hh"
+#include "globals.hh"
+#include "db.hh"
+#include "archive.hh"
+
+
+struct CopySink : DumpSink
+{
+    int fd;
+    virtual void operator () (const unsigned char * data, unsigned int len)
+    {
+        if (write(fd, (char *) data, len) != (ssize_t) len)
+            throw SysError("writing to child");
+    }
+};
+
+
+struct CopySource : RestoreSource
+{
+    int fd;
+    virtual void operator () (const unsigned char * data, unsigned int len)
+    {
+        ssize_t res = read(fd, (char *) data, len);
+        if (res == -1)
+            throw SysError("reading from parent");
+        if (res != (ssize_t) len)
+            throw Error("not enough data available on parent");
+    }
+};
+
+
+void copyPath(string src, string dst)
+{
+    /* Unfortunately C++ doesn't support coprocedures, so we have no
+       nice way to chain CopySink and CopySource together.  Instead we
+       fork off a child to run the sink.  (Fork-less platforms should
+       use a thread). */
+
+    /* Create a pipe. */
+    int fds[2];
+    if (pipe(fds) == -1) throw SysError("creating pipe");
+
+    /* Fork. */
+    pid_t pid;
+    switch (pid = fork()) {
+
+    case -1:
+        throw SysError("unable to fork");
+
+    case 0: /* child */
+        try {
+            close(fds[1]);
+            CopySource source;
+            source.fd = fds[0];
+            restorePath(dst, source);
+            _exit(0);
+        }  catch (exception & e) {
+            cerr << "error: " << e.what() << endl;
+        }
+        _exit(1);        
+    }
+
+    close(fds[0]);
+    
+    /* Parent. */
+
+    CopySink sink;
+    sink.fd = fds[1];
+    dumpPath(src, sink);
+
+    /* Wait for the child to finish. */
+    int status;
+    if (waitpid(pid, &status, 0) != pid)
+        throw SysError("waiting for child");
+
+    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+        throw Error("cannot copy file: child died");
+}
+
+
+void addToStore(string srcPath, string & dstPath, Hash & hash)
+{
+    srcPath = absPath(srcPath);
+
+    hash = hashPath(srcPath);
+
+    string path;
+    if (queryDB(nixDB, dbRefs, hash, path)) {
+        debug((string) hash + " already known");
+        dstPath = path;
+        return;
+    }
+
+    string baseName = baseNameOf(srcPath);
+    dstPath = nixStore + "/" + (string) hash + "-" + baseName;
+
+    copyPath(srcPath, dstPath);
+
+    setDB(nixDB, dbRefs, hash, dstPath);
+}
+
+
+void deleteFromStore(const string & path)
+{
+    string prefix = nixStore + "/";
+    if (string(path, 0, prefix.size()) != prefix)
+        throw Error(format("path %1% is not in the store") % path);
+    deletePath(path);
+//     delDB(nixDB, dbRefs, hash);
+}
+
+
+string queryFromStore(Hash hash)
+{
+    string fn, url;
+
+    if (queryDB(nixDB, dbRefs, hash, fn)) {
+        
+        /* Verify that the file hasn't changed. !!! race !!! slow */
+        if (hashPath(fn) != hash)
+            throw Error("file " + fn + " is stale");
+
+        return fn;
+    }
+
+    throw Error(format("don't know a path with hash `%1%'") % (string) hash);
+}
-- 
cgit 1.4.1