* Refactoring: move dump function into archive.cc.

This commit is contained in:
Eelco Dolstra 2003-06-20 10:40:25 +00:00
parent 38e12df631
commit 1849aa2a72
7 changed files with 190 additions and 183 deletions

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@ -3,13 +3,13 @@ noinst_PROGRAMS = test
AM_CXXFLAGS = -DSYSTEM=\"@host@\" -Wall -I..
nix_SOURCES = nix.cc util.cc hash.cc md5.c eval.cc values.cc globals.cc db.cc
nix_SOURCES = nix.cc util.cc hash.cc archive.cc md5.c eval.cc values.cc globals.cc db.cc
nix_LDADD = -ldb_cxx-4 -lATerm
#fix_SOURCES = fix.cc util.cc hash.cc md5.c
#fix_LDADD = -lATerm
test_SOURCES = test.cc util.cc hash.cc md5.c eval.cc values.cc globals.cc db.cc
test_SOURCES = test.cc util.cc hash.cc archive.cc md5.c eval.cc values.cc globals.cc db.cc
test_LDADD = -ldb_cxx-4 -lATerm
install-data-local:

136
src/archive.cc Normal file
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@ -0,0 +1,136 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
#include "archive.hh"
#include "util.hh"
static void pad(unsigned int len, DumpSink & sink)
{
if (len % 8) {
unsigned char zero[8];
memset(zero, 0, sizeof(zero));
sink(zero, 8 - (len % 8));
}
}
static void writeInt(unsigned int n, DumpSink & sink)
{
unsigned char buf[8];
memset(buf, 0, sizeof(buf));
buf[0] = n & 0xff;
buf[1] = (n >> 8) & 0xff;
buf[2] = (n >> 16) & 0xff;
buf[3] = (n >> 24) & 0xff;
sink(buf, sizeof(buf));
}
static void writeString(const string & s, DumpSink & sink)
{
unsigned int len = s.length();
writeInt(len, sink);
sink((const unsigned char *) s.c_str(), len);
pad(len, sink);
}
static void dumpEntries(const string & path, DumpSink & sink)
{
DIR * dir = opendir(path.c_str());
if (!dir) throw SysError("opening directory " + path);
Strings names;
struct dirent * dirent;
while (errno = 0, dirent = readdir(dir)) {
string name = dirent->d_name;
if (name == "." || name == "..") continue;
names.push_back(name);
}
if (errno) throw SysError("reading directory " + path);
sort(names.begin(), names.end());
for (Strings::iterator it = names.begin();
it != names.end(); it++)
{
writeString("entry", sink);
writeString("(", sink);
writeString("name", sink);
writeString(*it, sink);
writeString("file", sink);
dumpPath(path + "/" + *it, sink);
writeString(")", sink);
}
closedir(dir); /* !!! close on exception */
}
static void dumpContents(const string & path, unsigned int size,
DumpSink & sink)
{
writeString("contents", sink);
writeInt(size, sink);
int fd = open(path.c_str(), O_RDONLY);
if (!fd) throw SysError("opening file " + path);
unsigned char buf[65536];
unsigned int total = 0;
ssize_t n;
while ((n = read(fd, buf, sizeof(buf)))) {
if (n == -1) throw SysError("reading file " + path);
total += n;
sink(buf, n);
}
if (total != size)
throw SysError("file changed while reading it: " + path);
pad(size, sink);
close(fd); /* !!! close on exception */
}
void dumpPath(const string & path, DumpSink & sink)
{
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError("getting attributes of path " + path);
writeString("(", sink);
if (S_ISREG(st.st_mode)) {
writeString("type", sink);
writeString("regular", sink);
dumpContents(path, st.st_size, sink);
}
else if (S_ISDIR(st.st_mode)) {
writeString("type", sink);
writeString("directory", sink);
dumpEntries(path, sink);
}
else if (S_ISLNK(st.st_mode)) {
writeString("type", sink);
writeString("symlink", sink);
char buf[st.st_size];
if (readlink(path.c_str(), buf, st.st_size) != st.st_size)
throw SysError("reading symbolic link " + path);
writeString("target", sink);
writeString(string(buf, st.st_size), sink);
}
else throw Error("unknown file type: " + path);
writeString(")", sink);
}

48
src/archive.hh Normal file
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@ -0,0 +1,48 @@
#include <string>
using namespace std;
/* dumpPath creates a Nix archive of the specified path. The format
is as follows:
IF path points to a REGULAR FILE:
dump(path) = attrs(
[ ("type", "regular")
, ("contents", contents(path))
])
IF path points to a DIRECTORY:
dump(path) = attrs(
[ ("type", "directory")
, ("entries", concat(map(f, sort(entries(path)))))
])
where f(fn) = attrs(
[ ("name", fn)
, ("file", dump(path + "/" + fn))
])
where:
attrs(as) = concat(map(attr, as)) + encN(0)
attrs((a, b)) = encS(a) + encS(b)
encS(s) = encN(len(s)) + s + (padding until next 64-bit boundary)
encN(n) = 64-bit little-endian encoding of n.
contents(path) = the contents of a regular file.
sort(strings) = lexicographic sort by 8-bit value (strcmp).
entries(path) = the entries of a directory, without `.' and
`..'.
`+' denotes string concatenation. */
struct DumpSink
{
virtual void operator () (const unsigned char * data, unsigned int len) = 0;
};
void dumpPath(const string & path, DumpSink & sink);

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@ -1,16 +1,11 @@
#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
extern "C" {
#include "md5.h"
}
#include "hash.hh"
#include "archive.hh"
Hash::Hash()
@ -117,131 +112,3 @@ Hash hashPath(const string & path)
md5_finish_ctx(&sink.ctx, hash.hash);
return hash;
}
static void pad(unsigned int len, DumpSink & sink)
{
if (len % 8) {
unsigned char zero[8];
memset(zero, 0, sizeof(zero));
sink(zero, 8 - (len % 8));
}
}
static void writeInt(unsigned int n, DumpSink & sink)
{
unsigned char buf[8];
memset(buf, 0, sizeof(buf));
buf[0] = n & 0xff;
buf[1] = (n >> 8) & 0xff;
buf[2] = (n >> 16) & 0xff;
buf[3] = (n >> 24) & 0xff;
sink(buf, sizeof(buf));
}
static void writeString(const string & s, DumpSink & sink)
{
unsigned int len = s.length();
writeInt(len, sink);
sink((const unsigned char *) s.c_str(), len);
pad(len, sink);
}
static void dumpEntries(const string & path, DumpSink & sink)
{
DIR * dir = opendir(path.c_str());
if (!dir) throw SysError("opening directory " + path);
Strings names;
struct dirent * dirent;
while (errno = 0, dirent = readdir(dir)) {
string name = dirent->d_name;
if (name == "." || name == "..") continue;
names.push_back(name);
}
if (errno) throw SysError("reading directory " + path);
sort(names.begin(), names.end());
for (Strings::iterator it = names.begin();
it != names.end(); it++)
{
writeString("entry", sink);
writeString("(", sink);
writeString("name", sink);
writeString(*it, sink);
writeString("file", sink);
dumpPath(path + "/" + *it, sink);
writeString(")", sink);
}
closedir(dir); /* !!! close on exception */
}
static void dumpContents(const string & path, unsigned int size,
DumpSink & sink)
{
writeString("contents", sink);
writeInt(size, sink);
int fd = open(path.c_str(), O_RDONLY);
if (!fd) throw SysError("opening file " + path);
unsigned char buf[65536];
unsigned int total = 0;
ssize_t n;
while ((n = read(fd, buf, sizeof(buf)))) {
if (n == -1) throw SysError("reading file " + path);
total += n;
sink(buf, n);
}
if (total != size)
throw SysError("file changed while reading it: " + path);
pad(size, sink);
close(fd); /* !!! close on exception */
}
void dumpPath(const string & path, DumpSink & sink)
{
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError("getting attributes of path " + path);
writeString("(", sink);
if (S_ISREG(st.st_mode)) {
writeString("type", sink);
writeString("regular", sink);
dumpContents(path, st.st_size, sink);
}
else if (S_ISDIR(st.st_mode)) {
writeString("type", sink);
writeString("directory", sink);
dumpEntries(path, sink);
}
else if (S_ISLNK(st.st_mode)) {
writeString("type", sink);
writeString("symlink", sink);
char buf[st.st_size];
if (readlink(path.c_str(), buf, st.st_size) != st.st_size)
throw SysError("reading symbolic link " + path);
writeString("target", sink);
writeString(string(buf, st.st_size), sink);
}
else throw Error("unknown file type: " + path);
writeString(")", sink);
}

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@ -47,55 +47,9 @@ Hash hashString(const string & s);
Hash hashFile(const string & fileName);
/* Compute the hash of the given path. The hash is defined as
follows:
hash(path) = md5(dump(path))
md5(dump(path)).
*/
Hash hashPath(const string & path);
/* Dump a path as follows:
IF path points to a REGULAR FILE:
dump(path) = attrs(
[ ("type", "regular")
, ("contents", contents(path))
])
IF path points to a DIRECTORY:
dump(path) = attrs(
[ ("type", "directory")
, ("entries", concat(map(f, sort(entries(path)))))
])
where f(fn) = attrs(
[ ("name", fn)
, ("file", dump(path + "/" + fn))
])
where:
attrs(as) = concat(map(attr, as)) + encN(0)
attrs((a, b)) = encS(a) + encS(b)
encS(s) = encN(len(s)) + s + (padding until next 64-bit boundary)
encN(n) = 64-bit little-endian encoding of n.
contents(path) = the contents of a regular file.
sort(strings) = lexicographic sort by 8-bit value (strcmp).
entries(path) = the entries of a directory, without `.' and
`..'.
`+' denotes string concatenation. */
struct DumpSink
{
virtual void operator () (const unsigned char * data, unsigned int len) = 0;
};
void dumpPath(const string & path, DumpSink & sink);
#endif /* !__HASH_H */

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@ -5,6 +5,7 @@
#include "globals.hh"
#include "values.hh"
#include "eval.hh"
#include "archive.hh"
typedef void (* Operation) (Strings opFlags, Strings opArgs);

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@ -4,6 +4,7 @@
#include <sys/types.h>
#include "hash.hh"
#include "archive.hh"
#include "util.hh"
#include "eval.hh"
#include "values.hh"