Added extract.[ch]

git-svn-id: file:///home/lennart/svn/public/syrep/trunk@3 07ea20a6-d2c5-0310-9e02-9ef735347d72

1 files changed, 121 insertions, 0 deletions

diff --git a/src/extract.c b/src/extract.c
new file mode 100644
index 0000000..06d95df
--- /dev/null
+++ b/src/extract.c
@@ -0,0 +1,121 @@
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include "package.h"
+#include "extract.h"
+
+#define MMAPSIZE (100*1024*1024)
+#define BUFSIZE (1024*1024)
+
+int copy_file(const char *src, const char *dst, uint32_t l) {
+    int sfd = -1, dfd = -1, r = -1;
+    uint32_t m;
+    off_t o;
+    void *src_p, *dst_p;
+    void *buf = NULL;
+
+    if ((sfd = open(src, O_RDONLY)) < 0) {
+        fprintf(stderr, "open(%s, O_RDONLY): %s\n", src, strerror(errno));
+        goto finish;
+    }
+
+    if ((dfd = open(dst, O_RDWR|O_TRUNC|O_CREAT, 0666)) < 0) {
+        fprintf(stderr, "open(%s, O_WRONLY): %s\n", dst, strerror(errno));
+        goto finish;
+    }
+
+    if (ftruncate(dfd, l) < 0) {
+        fprintf(stderr, "ftruncate(): %s\n", strerror(errno));
+        goto finish;
+    }
+
+    o = 0;
+    m = l < MMAPSIZE ? l : MMAPSIZE;
+
+    while (l > 0) {
+        if ((src_p = mmap(NULL, m, PROT_READ, MAP_SHARED, sfd, o)) == MAP_FAILED)
+            break;
+        
+        if ((dst_p = mmap(NULL, m, PROT_READ|PROT_WRITE, MAP_SHARED, dfd, o)) == MAP_FAILED) {
+            munmap(src_p, m);
+            break;
+        }
+        
+        memcpy(dst_p, src_p, m);
+
+        munmap(src_p, m);
+        munmap(dst_p, m);
+        
+        o += m;
+        l -= m;
+        m = l < MMAPSIZE ? l : MMAPSIZE;
+    }
+
+    if (l > 0) {
+        fprintf(stderr, "mmap() failed: %s\n", strerror(errno));
+
+        if (!(buf = malloc(BUFSIZE)))
+            goto finish;
+
+        for (;;) {
+            ssize_t r;
+
+            if ((m = read(sfd, buf, BUFSIZE)) < 0) {
+                fprintf(stderr, "read(): %s\n", strerror(errno));
+                goto finish;
+            }
+
+            if (!m)
+                break;
+                
+            if ((r = write(dfd, buf, m)) < 0) {
+                fprintf(stderr, "write(): %s\n", strerror(errno));
+                goto finish;
+            }
+        }
+    }
+
+    
+    r = 0;
+
+finish:
+    
+    if (sfd >= 0)
+        close(sfd);
+
+    if (dfd >= 0)
+        close(dfd);
+
+    return r;
+}
+
+static int cb(struct package *p, const char *name, const char *path, void *u) {
+    struct stat st;
+    uint32_t size;
+
+    if (stat(path, &st) < 0) {
+        if (errno == ENOENT)
+            size = 0;
+        else {
+            fprintf(stderr, "stat(%s) failed: %s\n", path, strerror(errno));
+            return -1;
+        }
+    } else
+        size = (uint32_t) st.st_size;
+
+    if (size)
+        return copy_file(path, name, size);
+
+    return 0;
+}
+
+int extract(struct syrep_db_context *context) {
+    return package_foreach(context->package, cb, NULL);
+}