forked from lix-project/lix
* A function to restore from a Nix archive.
* addValue() can now import any dumpable FS object.
This commit is contained in:
parent
85effedca3
commit
5f5cab0ac7
196
src/archive.cc
196
src/archive.cc
|
@ -10,7 +10,10 @@
|
||||||
#include "util.hh"
|
#include "util.hh"
|
||||||
|
|
||||||
|
|
||||||
static void pad(unsigned int len, DumpSink & sink)
|
static string archiveVersion1 = "nix-archive-1";
|
||||||
|
|
||||||
|
|
||||||
|
static void writePadding(unsigned int len, DumpSink & sink)
|
||||||
{
|
{
|
||||||
if (len % 8) {
|
if (len % 8) {
|
||||||
unsigned char zero[8];
|
unsigned char zero[8];
|
||||||
|
@ -37,10 +40,13 @@ static void writeString(const string & s, DumpSink & sink)
|
||||||
unsigned int len = s.length();
|
unsigned int len = s.length();
|
||||||
writeInt(len, sink);
|
writeInt(len, sink);
|
||||||
sink((const unsigned char *) s.c_str(), len);
|
sink((const unsigned char *) s.c_str(), len);
|
||||||
pad(len, sink);
|
writePadding(len, sink);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static void dump(const string & path, DumpSink & sink);
|
||||||
|
|
||||||
|
|
||||||
static void dumpEntries(const string & path, DumpSink & sink)
|
static void dumpEntries(const string & path, DumpSink & sink)
|
||||||
{
|
{
|
||||||
DIR * dir = opendir(path.c_str());
|
DIR * dir = opendir(path.c_str());
|
||||||
|
@ -65,8 +71,8 @@ static void dumpEntries(const string & path, DumpSink & sink)
|
||||||
writeString("(", sink);
|
writeString("(", sink);
|
||||||
writeString("name", sink);
|
writeString("name", sink);
|
||||||
writeString(*it, sink);
|
writeString(*it, sink);
|
||||||
writeString("file", sink);
|
writeString("node", sink);
|
||||||
dumpPath(path + "/" + *it, sink);
|
dump(path + "/" + *it, sink);
|
||||||
writeString(")", sink);
|
writeString(")", sink);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -96,13 +102,13 @@ static void dumpContents(const string & path, unsigned int size,
|
||||||
if (total != size)
|
if (total != size)
|
||||||
throw SysError("file changed while reading it: " + path);
|
throw SysError("file changed while reading it: " + path);
|
||||||
|
|
||||||
pad(size, sink);
|
writePadding(size, sink);
|
||||||
|
|
||||||
close(fd); /* !!! close on exception */
|
close(fd); /* !!! close on exception */
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
void dumpPath(const string & path, DumpSink & sink)
|
static void dump(const string & path, DumpSink & sink)
|
||||||
{
|
{
|
||||||
struct stat st;
|
struct stat st;
|
||||||
if (lstat(path.c_str(), &st))
|
if (lstat(path.c_str(), &st))
|
||||||
|
@ -138,6 +144,182 @@ void dumpPath(const string & path, DumpSink & sink)
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
void restorePath(const string & path, ReadSource & source)
|
void dumpPath(const string & path, DumpSink & sink)
|
||||||
{
|
{
|
||||||
|
writeString(archiveVersion1, sink);
|
||||||
|
dump(path, sink);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static Error badArchive(string s)
|
||||||
|
{
|
||||||
|
return Error("bad archive: " + s);
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static void readPadding(unsigned int len, RestoreSource & source)
|
||||||
|
{
|
||||||
|
if (len % 8) {
|
||||||
|
unsigned char zero[8];
|
||||||
|
unsigned int n = 8 - (len % 8);
|
||||||
|
source(zero, n);
|
||||||
|
for (unsigned int i = 0; i < n; i++)
|
||||||
|
if (zero[i]) throw badArchive("non-zero padding");
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static unsigned int readInt(RestoreSource & source)
|
||||||
|
{
|
||||||
|
unsigned char buf[8];
|
||||||
|
source(buf, sizeof(buf));
|
||||||
|
if (buf[4] || buf[5] || buf[6] || buf[7])
|
||||||
|
throw Error("implementation cannot deal with > 32-bit integers");
|
||||||
|
return
|
||||||
|
buf[0] |
|
||||||
|
(buf[1] << 8) |
|
||||||
|
(buf[2] << 16) |
|
||||||
|
(buf[3] << 24);
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static string readString(RestoreSource & source)
|
||||||
|
{
|
||||||
|
unsigned int len = readInt(source);
|
||||||
|
char buf[len];
|
||||||
|
source((const unsigned char *) buf, len);
|
||||||
|
readPadding(len, source);
|
||||||
|
return string(buf, len);
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static void skipGeneric(RestoreSource & source)
|
||||||
|
{
|
||||||
|
if (readString(source) == "(") {
|
||||||
|
while (readString(source) != ")")
|
||||||
|
skipGeneric(source);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static void restore(const string & path, RestoreSource & source);
|
||||||
|
|
||||||
|
|
||||||
|
static void restoreEntry(const string & path, RestoreSource & source)
|
||||||
|
{
|
||||||
|
string s, name;
|
||||||
|
|
||||||
|
s = readString(source);
|
||||||
|
if (s != "(") throw badArchive("expected open tag");
|
||||||
|
|
||||||
|
while (1) {
|
||||||
|
s = readString(source);
|
||||||
|
|
||||||
|
if (s == ")") {
|
||||||
|
break;
|
||||||
|
} else if (s == "name") {
|
||||||
|
name = readString(source);
|
||||||
|
} else if (s == "node") {
|
||||||
|
if (s == "") throw badArchive("entry name missing");
|
||||||
|
restore(path + "/" + name, source);
|
||||||
|
} else {
|
||||||
|
throw badArchive("unknown field " + s);
|
||||||
|
skipGeneric(source);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static void restoreContents(int fd, const string & path, RestoreSource & source)
|
||||||
|
{
|
||||||
|
unsigned int size = readInt(source);
|
||||||
|
unsigned int left = size;
|
||||||
|
unsigned char buf[65536];
|
||||||
|
|
||||||
|
while (left) {
|
||||||
|
unsigned int n = sizeof(buf);
|
||||||
|
if (n > left) n = left;
|
||||||
|
source(buf, n);
|
||||||
|
if (write(fd, buf, n) != (ssize_t) n)
|
||||||
|
throw SysError("writing file " + path);
|
||||||
|
left -= n;
|
||||||
|
}
|
||||||
|
|
||||||
|
readPadding(size, source);
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
static void restore(const string & path, RestoreSource & source)
|
||||||
|
{
|
||||||
|
string s;
|
||||||
|
|
||||||
|
s = readString(source);
|
||||||
|
if (s != "(") throw badArchive("expected open tag");
|
||||||
|
|
||||||
|
enum { tpUnknown, tpRegular, tpDirectory, tpSymlink } type = tpUnknown;
|
||||||
|
int fd = -1; /* !!! close on exception */
|
||||||
|
|
||||||
|
while (1) {
|
||||||
|
s = readString(source);
|
||||||
|
|
||||||
|
if (s == ")") {
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
|
||||||
|
else if (s == "type") {
|
||||||
|
if (type != tpUnknown)
|
||||||
|
throw badArchive("multiple type fields");
|
||||||
|
string t = readString(source);
|
||||||
|
|
||||||
|
if (t == "regular") {
|
||||||
|
type = tpRegular;
|
||||||
|
fd = open(path.c_str(), O_CREAT | O_EXCL | O_WRONLY, 0666);
|
||||||
|
if (fd == -1)
|
||||||
|
throw SysError("creating file " + path);
|
||||||
|
}
|
||||||
|
|
||||||
|
else if (t == "directory") {
|
||||||
|
type = tpDirectory;
|
||||||
|
if (mkdir(path.c_str(), 0777) == -1)
|
||||||
|
throw SysError("creating directory " + path);
|
||||||
|
}
|
||||||
|
|
||||||
|
else if (t == "symlink") {
|
||||||
|
type = tpSymlink;
|
||||||
|
}
|
||||||
|
|
||||||
|
else throw badArchive("unknown file type " + t);
|
||||||
|
|
||||||
|
}
|
||||||
|
|
||||||
|
else if (s == "contents" && type == tpRegular) {
|
||||||
|
restoreContents(fd, path, source);
|
||||||
|
}
|
||||||
|
|
||||||
|
else if (s == "entry" && type == tpDirectory) {
|
||||||
|
restoreEntry(path, source);
|
||||||
|
}
|
||||||
|
|
||||||
|
else if (s == "target" && type == tpSymlink) {
|
||||||
|
string target = readString(source);
|
||||||
|
if (symlink(target.c_str(), path.c_str()) == -1)
|
||||||
|
throw SysError("creating symlink " + path);
|
||||||
|
}
|
||||||
|
|
||||||
|
else {
|
||||||
|
throw badArchive("unknown field " + s);
|
||||||
|
skipGeneric(source);
|
||||||
|
}
|
||||||
|
|
||||||
|
}
|
||||||
|
|
||||||
|
if (fd != -1) close(fd);
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
void restorePath(const string & path, RestoreSource & source)
|
||||||
|
{
|
||||||
|
if (readString(source) != archiveVersion1)
|
||||||
|
throw badArchive("expected Nix archive");
|
||||||
|
restore(path, source);
|
||||||
|
}
|
||||||
|
|
||||||
|
|
|
@ -48,7 +48,7 @@ struct DumpSink
|
||||||
void dumpPath(const string & path, DumpSink & sink);
|
void dumpPath(const string & path, DumpSink & sink);
|
||||||
|
|
||||||
|
|
||||||
struct ReadSource
|
struct RestoreSource
|
||||||
{
|
{
|
||||||
/* The callee should store exactly *len bytes in the buffer
|
/* The callee should store exactly *len bytes in the buffer
|
||||||
pointed to by data. It should block if that much data is not
|
pointed to by data. It should block if that much data is not
|
||||||
|
@ -56,3 +56,5 @@ struct ReadSource
|
||||||
available. */
|
available. */
|
||||||
virtual void operator () (const unsigned char * data, unsigned int len) = 0;
|
virtual void operator () (const unsigned char * data, unsigned int len) = 0;
|
||||||
};
|
};
|
||||||
|
|
||||||
|
void restorePath(const string & path, RestoreSource & source);
|
||||||
|
|
|
@ -123,8 +123,8 @@ static Hash computeDerived(Hash sourceHash, string targetName,
|
||||||
|
|
||||||
} catch (exception & e) {
|
} catch (exception & e) {
|
||||||
cerr << "build error: " << e.what() << endl;
|
cerr << "build error: " << e.what() << endl;
|
||||||
_exit(1);
|
|
||||||
}
|
}
|
||||||
|
_exit(1);
|
||||||
|
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
|
@ -133,7 +133,8 @@ struct StdoutSink : DumpSink
|
||||||
(const unsigned char * data, unsigned int len)
|
(const unsigned char * data, unsigned int len)
|
||||||
{
|
{
|
||||||
/* Don't use cout, it's slow as hell! */
|
/* Don't use cout, it's slow as hell! */
|
||||||
write(STDOUT_FILENO, (char *) data, len);
|
if (write(STDOUT_FILENO, (char *) data, len) != len)
|
||||||
|
throw SysError("writing to stdout");
|
||||||
}
|
}
|
||||||
};
|
};
|
||||||
|
|
||||||
|
|
24
src/test.cc
24
src/test.cc
|
@ -23,7 +23,21 @@ struct MySink : DumpSink
|
||||||
virtual void operator () (const unsigned char * data, unsigned int len)
|
virtual void operator () (const unsigned char * data, unsigned int len)
|
||||||
{
|
{
|
||||||
/* Don't use cout, it's slow as hell! */
|
/* Don't use cout, it's slow as hell! */
|
||||||
write(STDOUT_FILENO, (char *) data, len);
|
if (write(STDOUT_FILENO, (char *) data, len) != (ssize_t) len)
|
||||||
|
throw SysError("writing to stdout");
|
||||||
|
}
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
struct MySource : RestoreSource
|
||||||
|
{
|
||||||
|
virtual void operator () (const unsigned char * data, unsigned int len)
|
||||||
|
{
|
||||||
|
ssize_t res = read(STDIN_FILENO, (char *) data, len);
|
||||||
|
if (res == -1)
|
||||||
|
throw SysError("reading from stdin");
|
||||||
|
if (res != (ssize_t) len)
|
||||||
|
throw Error("not enough data available on stdin");
|
||||||
}
|
}
|
||||||
};
|
};
|
||||||
|
|
||||||
|
@ -53,6 +67,14 @@ void runTests()
|
||||||
cout << (string) hashPath("scratch") << endl;
|
cout << (string) hashPath("scratch") << endl;
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
|
/* Restoring. */
|
||||||
|
#if 1
|
||||||
|
MySource source;
|
||||||
|
restorePath("outdir", source);
|
||||||
|
cout << (string) hashPath("outdir") << endl;
|
||||||
|
return;
|
||||||
|
#endif
|
||||||
|
|
||||||
/* Set up the test environment. */
|
/* Set up the test environment. */
|
||||||
|
|
||||||
mkdir("scratch", 0777);
|
mkdir("scratch", 0777);
|
||||||
|
|
|
@ -1,13 +1,85 @@
|
||||||
|
#include <iostream>
|
||||||
|
|
||||||
|
#include <sys/types.h>
|
||||||
|
#include <sys/wait.h>
|
||||||
|
|
||||||
#include "values.hh"
|
#include "values.hh"
|
||||||
#include "globals.hh"
|
#include "globals.hh"
|
||||||
#include "db.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");
|
||||||
|
}
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
static void copyFile(string src, string dst)
|
static void copyFile(string src, string dst)
|
||||||
{
|
{
|
||||||
int res = system(("cat " + src + " > " + dst).c_str()); /* !!! escape */
|
/* Unfortunately C++ doesn't support coprocedures, so we have no
|
||||||
if (WEXITSTATUS(res) != 0)
|
nice way to chain CopySink and CopySource together. Instead we
|
||||||
throw Error("cannot copy " + src + " to " + dst);
|
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");
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
|
Loading…
Reference in a new issue