diff options
Diffstat (limited to 'minzip/SysUtil.c')
-rw-r--r-- | minzip/SysUtil.c | 239 |
1 files changed, 120 insertions, 119 deletions
diff --git a/minzip/SysUtil.c b/minzip/SysUtil.c index 31c76d6..c046a8c 100644 --- a/minzip/SysUtil.c +++ b/minzip/SysUtil.c @@ -8,42 +8,17 @@ #include <unistd.h> #include <string.h> #include <sys/mman.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> #include <limits.h> #include <errno.h> #include <assert.h> -#define LOG_TAG "minzip" +#define LOG_TAG "sysutil" #include "Log.h" #include "SysUtil.h" -/* - * Having trouble finding a portable way to get this. sysconf(_SC_PAGE_SIZE) - * seems appropriate, but we don't have that on the device. Some systems - * have getpagesize(2), though the linux man page has some odd cautions. - */ -#define DEFAULT_PAGE_SIZE 4096 - - -/* - * Create an anonymous shared memory segment large enough to hold "length" - * bytes. The actual segment may be larger because mmap() operates on - * page boundaries (usually 4K). - */ -static void* sysCreateAnonShmem(size_t length) -{ - void* ptr; - - ptr = mmap(NULL, length, PROT_READ | PROT_WRITE, - MAP_SHARED | MAP_ANON, -1, 0); - if (ptr == MAP_FAILED) { - LOGW("mmap(%d, RW, SHARED|ANON) failed: %s\n", (int) length, - strerror(errno)); - return NULL; - } - - return ptr; -} - static int getFileStartAndLength(int fd, off_t *start_, size_t *length_) { off_t start, end; @@ -74,48 +49,13 @@ static int getFileStartAndLength(int fd, off_t *start_, size_t *length_) } /* - * Pull the contents of a file into an new shared memory segment. We grab - * everything from fd's current offset on. - * - * We need to know the length ahead of time so we can allocate a segment - * of sufficient size. - */ -int sysLoadFileInShmem(int fd, MemMapping* pMap) -{ - off_t start; - size_t length, actual; - void* memPtr; - - assert(pMap != NULL); - - if (getFileStartAndLength(fd, &start, &length) < 0) - return -1; - - memPtr = sysCreateAnonShmem(length); - if (memPtr == NULL) - return -1; - - pMap->baseAddr = pMap->addr = memPtr; - pMap->baseLength = pMap->length = length; - - actual = TEMP_FAILURE_RETRY(read(fd, memPtr, length)); - if (actual != length) { - LOGE("only read %d of %d bytes\n", (int) actual, (int) length); - sysReleaseShmem(pMap); - return -1; - } - - return 0; -} - -/* - * Map a file (from fd's current offset) into a shared, read-only memory + * Map a file (from fd's current offset) into a private, read-only memory * segment. The file offset must be a multiple of the page size. * * On success, returns 0 and fills out "pMap". On failure, returns a nonzero * value and does not disturb "pMap". */ -int sysMapFileInShmem(int fd, MemMapping* pMap) +static int sysMapFD(int fd, MemMapping* pMap) { off_t start; size_t length; @@ -126,87 +66,148 @@ int sysMapFileInShmem(int fd, MemMapping* pMap) if (getFileStartAndLength(fd, &start, &length) < 0) return -1; - memPtr = mmap(NULL, length, PROT_READ, MAP_FILE | MAP_SHARED, fd, start); + memPtr = mmap(NULL, length, PROT_READ, MAP_PRIVATE, fd, start); if (memPtr == MAP_FAILED) { - LOGW("mmap(%d, R, FILE|SHARED, %d, %d) failed: %s\n", (int) length, + LOGW("mmap(%d, R, PRIVATE, %d, %d) failed: %s\n", (int) length, fd, (int) start, strerror(errno)); return -1; } - pMap->baseAddr = pMap->addr = memPtr; - pMap->baseLength = pMap->length = length; + pMap->addr = memPtr; + pMap->length = length; + pMap->range_count = 1; + pMap->ranges = malloc(sizeof(MappedRange)); + pMap->ranges[0].addr = memPtr; + pMap->ranges[0].length = length; return 0; } -/* - * Map part of a file (from fd's current offset) into a shared, read-only - * memory segment. - * - * On success, returns 0 and fills out "pMap". On failure, returns a nonzero - * value and does not disturb "pMap". - */ -int sysMapFileSegmentInShmem(int fd, off_t start, long length, - MemMapping* pMap) +static int sysMapBlockFile(FILE* mapf, MemMapping* pMap) { - off_t dummy; - size_t fileLength, actualLength; - off_t actualStart; - int adjust; - void* memPtr; - - assert(pMap != NULL); + char block_dev[PATH_MAX+1]; + size_t size; + unsigned int blksize; + unsigned int blocks; + unsigned int range_count; + unsigned int i; + + if (fgets(block_dev, sizeof(block_dev), mapf) == NULL) { + LOGW("failed to read block device from header\n"); + return -1; + } + for (i = 0; i < sizeof(block_dev); ++i) { + if (block_dev[i] == '\n') { + block_dev[i] = 0; + break; + } + } - if (getFileStartAndLength(fd, &dummy, &fileLength) < 0) + if (fscanf(mapf, "%d %d\n%d\n", &size, &blksize, &range_count) != 3) { + LOGW("failed to parse block map header\n"); return -1; + } - if (start + length > (long)fileLength) { - LOGW("bad segment: st=%d len=%ld flen=%d\n", - (int) start, length, (int) fileLength); + blocks = ((size-1) / blksize) + 1; + + pMap->range_count = range_count; + pMap->ranges = malloc(range_count * sizeof(MappedRange)); + memset(pMap->ranges, 0, range_count * sizeof(MappedRange)); + + // Reserve enough contiguous address space for the whole file. + unsigned char* reserve; + reserve = mmap64(NULL, blocks * blksize, PROT_NONE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (reserve == MAP_FAILED) { + LOGW("failed to reserve address space: %s\n", strerror(errno)); return -1; } - /* adjust to be page-aligned */ - adjust = start % DEFAULT_PAGE_SIZE; - actualStart = start - adjust; - actualLength = length + adjust; + pMap->ranges[range_count-1].addr = reserve; + pMap->ranges[range_count-1].length = blocks * blksize; - memPtr = mmap(NULL, actualLength, PROT_READ, MAP_FILE | MAP_SHARED, - fd, actualStart); - if (memPtr == MAP_FAILED) { - LOGW("mmap(%d, R, FILE|SHARED, %d, %d) failed: %s\n", - (int) actualLength, fd, (int) actualStart, strerror(errno)); + int fd = open(block_dev, O_RDONLY); + if (fd < 0) { + LOGW("failed to open block device %s: %s\n", block_dev, strerror(errno)); return -1; } - pMap->baseAddr = memPtr; - pMap->baseLength = actualLength; - pMap->addr = (char*)memPtr + adjust; - pMap->length = length; + unsigned char* next = reserve; + for (i = 0; i < range_count; ++i) { + int start, end; + if (fscanf(mapf, "%d %d\n", &start, &end) != 2) { + LOGW("failed to parse range %d in block map\n", i); + return -1; + } + + void* addr = mmap64(next, (end-start)*blksize, PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, ((off64_t)start)*blksize); + if (addr == MAP_FAILED) { + LOGW("failed to map block %d: %s\n", i, strerror(errno)); + return -1; + } + pMap->ranges[i].addr = addr; + pMap->ranges[i].length = (end-start)*blksize; + + next += pMap->ranges[i].length; + } + + pMap->addr = reserve; + pMap->length = size; - LOGVV("mmap seg (st=%d ln=%d): bp=%p bl=%d ad=%p ln=%d\n", - (int) start, (int) length, - pMap->baseAddr, (int) pMap->baseLength, - pMap->addr, (int) pMap->length); + LOGI("mmapped %d ranges\n", range_count); return 0; } +int sysMapFile(const char* fn, MemMapping* pMap) +{ + memset(pMap, 0, sizeof(*pMap)); + + if (fn && fn[0] == '@') { + // A map of blocks + FILE* mapf = fopen(fn+1, "r"); + if (mapf == NULL) { + LOGV("Unable to open '%s': %s\n", fn+1, strerror(errno)); + return -1; + } + + if (sysMapBlockFile(mapf, pMap) != 0) { + LOGW("Map of '%s' failed\n", fn); + return -1; + } + + fclose(mapf); + } else { + // This is a regular file. + int fd = open(fn, O_RDONLY, 0); + if (fd < 0) { + LOGE("Unable to open '%s': %s\n", fn, strerror(errno)); + return -1; + } + + if (sysMapFD(fd, pMap) != 0) { + LOGE("Map of '%s' failed\n", fn); + close(fd); + return -1; + } + + close(fd); + } + return 0; +} + /* * Release a memory mapping. */ -void sysReleaseShmem(MemMapping* pMap) +void sysReleaseMap(MemMapping* pMap) { - if (pMap->baseAddr == NULL && pMap->baseLength == 0) - return; - - if (munmap(pMap->baseAddr, pMap->baseLength) < 0) { - LOGW("munmap(%p, %d) failed: %s\n", - pMap->baseAddr, (int)pMap->baseLength, strerror(errno)); - } else { - LOGV("munmap(%p, %d) succeeded\n", pMap->baseAddr, pMap->baseLength); - pMap->baseAddr = NULL; - pMap->baseLength = 0; + int i; + for (i = 0; i < pMap->range_count; ++i) { + if (munmap(pMap->ranges[i].addr, pMap->ranges[i].length) < 0) { + LOGW("munmap(%p, %d) failed: %s\n", + pMap->ranges[i].addr, (int)pMap->ranges[i].length, strerror(errno)); + } } + free(pMap->ranges); + pMap->ranges = NULL; + pMap->range_count = 0; } - |