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authorEelco Dolstra <e.dolstra@tudelft.nl>2003-07-07 07:43:58 +0000
committerEelco Dolstra <e.dolstra@tudelft.nl>2003-07-07 07:43:58 +0000
commit224c585aba5e450fa47e41c4cc19dac2d0c6fe2a (patch)
treec01d0ce342be0d7aacb7c95e8b8f85d6cd4ec53f /src/store.cc
parent7952a8053c474e771d6ee14e3ab6dc15c9ddd895 (diff)
* Refactoring on the file names.
Diffstat (limited to 'src/store.cc')
-rw-r--r--src/store.cc132
1 files changed, 132 insertions, 0 deletions
diff --git a/src/store.cc b/src/store.cc
new file mode 100644
index 000000000..68a1cd1e2
--- /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);
+}