From: Linus Torvalds Date: Mon, 18 Apr 2005 20:04:43 +0000 (-0700) Subject: Split up read-cache.c into more logical clumps. X-Git-Tag: v0.99~830 X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=0fcfd160b0495c0881e142c546c4418b8cea7e93;p=git.git Split up read-cache.c into more logical clumps. Do the usage and error reporting in "usage.c", and the sha1 file accesses in "sha1_file.c". Small, nice, easily separated parts. Good. --- diff --git a/Makefile b/Makefile index 3438df3b..424c4e43 100644 --- a/Makefile +++ b/Makefile @@ -22,7 +22,7 @@ all: $(PROG) install: $(PROG) install $(PROG) $(HOME)/bin/ -LIB_OBJS=read-cache.o object.o commit.o tree.o blob.o +LIB_OBJS=read-cache.o sha1_file.o usage.o object.o commit.o tree.o blob.o LIB_FILE=libgit.a $(LIB_FILE): $(LIB_OBJS) diff --git a/read-cache.c b/read-cache.c index 8571ba2f..bfa2de76 100644 --- a/read-cache.c +++ b/read-cache.c @@ -6,279 +6,9 @@ #include #include "cache.h" -const char *sha1_file_directory = NULL; struct cache_entry **active_cache = NULL; unsigned int active_nr = 0, active_alloc = 0; -void usage(const char *err) -{ - fprintf(stderr, "usage: %s\n", err); - exit(1); -} - -static void report(const char *prefix, const char *err, va_list params) -{ - fputs(prefix, stderr); - vfprintf(stderr, err, params); - fputs("\n", stderr); -} - -void die(const char *err, ...) -{ - va_list params; - - va_start(params, err); - report("fatal: ", err, params); - va_end(params); - exit(1); -} - -int error(const char *err, ...) -{ - va_list params; - - va_start(params, err); - report("error: ", err, params); - va_end(params); - return -1; -} - - -static unsigned hexval(char c) -{ - if (c >= '0' && c <= '9') - return c - '0'; - if (c >= 'a' && c <= 'f') - return c - 'a' + 10; - if (c >= 'A' && c <= 'F') - return c - 'A' + 10; - return ~0; -} - -int get_sha1_hex(const char *hex, unsigned char *sha1) -{ - int i; - for (i = 0; i < 20; i++) { - unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]); - if (val & ~0xff) - return -1; - *sha1++ = val; - hex += 2; - } - return 0; -} - -char * sha1_to_hex(const unsigned char *sha1) -{ - static char buffer[50]; - static const char hex[] = "0123456789abcdef"; - char *buf = buffer; - int i; - - for (i = 0; i < 20; i++) { - unsigned int val = *sha1++; - *buf++ = hex[val >> 4]; - *buf++ = hex[val & 0xf]; - } - return buffer; -} - -/* - * NOTE! This returns a statically allocated buffer, so you have to be - * careful about using it. Do a "strdup()" if you need to save the - * filename. - */ -char *sha1_file_name(const unsigned char *sha1) -{ - int i; - static char *name, *base; - - if (!base) { - char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT; - int len = strlen(sha1_file_directory); - base = malloc(len + 60); - memcpy(base, sha1_file_directory, len); - memset(base+len, 0, 60); - base[len] = '/'; - base[len+3] = '/'; - name = base + len + 1; - } - for (i = 0; i < 20; i++) { - static char hex[] = "0123456789abcdef"; - unsigned int val = sha1[i]; - char *pos = name + i*2 + (i > 0); - *pos++ = hex[val >> 4]; - *pos = hex[val & 0xf]; - } - return base; -} - -int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size) -{ - unsigned char real_sha1[20]; - SHA_CTX c; - - SHA1_Init(&c); - SHA1_Update(&c, map, size); - SHA1_Final(real_sha1, &c); - return memcmp(sha1, real_sha1, 20) ? -1 : 0; -} - -void *map_sha1_file(const unsigned char *sha1, unsigned long *size) -{ - char *filename = sha1_file_name(sha1); - int fd = open(filename, O_RDONLY); - struct stat st; - void *map; - - if (fd < 0) { - perror(filename); - return NULL; - } - if (fstat(fd, &st) < 0) { - close(fd); - return NULL; - } - map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); - close(fd); - if (-1 == (int)(long)map) - return NULL; - *size = st.st_size; - return map; -} - -void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size) -{ - int ret, bytes; - z_stream stream; - char buffer[8192]; - char *buf; - - /* Get the data stream */ - memset(&stream, 0, sizeof(stream)); - stream.next_in = map; - stream.avail_in = mapsize; - stream.next_out = buffer; - stream.avail_out = sizeof(buffer); - - inflateInit(&stream); - ret = inflate(&stream, 0); - if (sscanf(buffer, "%10s %lu", type, size) != 2) - return NULL; - - bytes = strlen(buffer) + 1; - buf = malloc(*size); - if (!buf) - return NULL; - - memcpy(buf, buffer + bytes, stream.total_out - bytes); - bytes = stream.total_out - bytes; - if (bytes < *size && ret == Z_OK) { - stream.next_out = buf + bytes; - stream.avail_out = *size - bytes; - while (inflate(&stream, Z_FINISH) == Z_OK) - /* nothing */; - } - inflateEnd(&stream); - return buf; -} - -void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size) -{ - unsigned long mapsize; - void *map, *buf; - - map = map_sha1_file(sha1, &mapsize); - if (map) { - buf = unpack_sha1_file(map, mapsize, type, size); - munmap(map, mapsize); - return buf; - } - return NULL; -} - -int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1) -{ - int size; - char *compressed; - z_stream stream; - unsigned char sha1[20]; - SHA_CTX c; - - /* Set it up */ - memset(&stream, 0, sizeof(stream)); - deflateInit(&stream, Z_BEST_COMPRESSION); - size = deflateBound(&stream, len); - compressed = malloc(size); - - /* Compress it */ - stream.next_in = buf; - stream.avail_in = len; - stream.next_out = compressed; - stream.avail_out = size; - while (deflate(&stream, Z_FINISH) == Z_OK) - /* nothing */; - deflateEnd(&stream); - size = stream.total_out; - - /* Sha1.. */ - SHA1_Init(&c); - SHA1_Update(&c, compressed, size); - SHA1_Final(sha1, &c); - - if (write_sha1_buffer(sha1, compressed, size) < 0) - return -1; - if (returnsha1) - memcpy(returnsha1, sha1, 20); - return 0; -} - -static inline int collision_check(char *filename, void *buf, unsigned int size) -{ -#ifdef COLLISION_CHECK - void *map; - int fd = open(filename, O_RDONLY); - struct stat st; - int cmp; - - /* Unreadable object, or object went away? Strange. */ - if (fd < 0) - return -1; - - if (fstat(fd, &st) < 0 || size != st.st_size) - return -1; - - map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); - close(fd); - if (map == MAP_FAILED) - return -1; - cmp = memcmp(buf, map, size); - munmap(map, size); - if (cmp) - return -1; -#endif - return 0; -} - -int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size) -{ - char *filename = sha1_file_name(sha1); - int fd; - - fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666); - if (fd < 0) { - if (errno != EEXIST) - return -1; - if (collision_check(filename, buf, size)) - return error("SHA1 collision detected!" - " This is bad, bad, BAD!\a\n"); - return 0; - } - write(fd, buf, size); - close(fd); - return 0; -} - int cache_match_stat(struct cache_entry *ce, struct stat *st) { unsigned int changed = 0; diff --git a/sha1_file.c b/sha1_file.c new file mode 100644 index 00000000..bb44a017 --- /dev/null +++ b/sha1_file.c @@ -0,0 +1,247 @@ +/* + * GIT - The information manager from hell + * + * Copyright (C) Linus Torvalds, 2005 + * + * This handles basic git sha1 object files - packing, unpacking, + * creation etc. + */ +#include +#include "cache.h" + +const char *sha1_file_directory = NULL; + +static unsigned hexval(char c) +{ + if (c >= '0' && c <= '9') + return c - '0'; + if (c >= 'a' && c <= 'f') + return c - 'a' + 10; + if (c >= 'A' && c <= 'F') + return c - 'A' + 10; + return ~0; +} + +int get_sha1_hex(const char *hex, unsigned char *sha1) +{ + int i; + for (i = 0; i < 20; i++) { + unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]); + if (val & ~0xff) + return -1; + *sha1++ = val; + hex += 2; + } + return 0; +} + +char * sha1_to_hex(const unsigned char *sha1) +{ + static char buffer[50]; + static const char hex[] = "0123456789abcdef"; + char *buf = buffer; + int i; + + for (i = 0; i < 20; i++) { + unsigned int val = *sha1++; + *buf++ = hex[val >> 4]; + *buf++ = hex[val & 0xf]; + } + return buffer; +} + +/* + * NOTE! This returns a statically allocated buffer, so you have to be + * careful about using it. Do a "strdup()" if you need to save the + * filename. + */ +char *sha1_file_name(const unsigned char *sha1) +{ + int i; + static char *name, *base; + + if (!base) { + char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT; + int len = strlen(sha1_file_directory); + base = malloc(len + 60); + memcpy(base, sha1_file_directory, len); + memset(base+len, 0, 60); + base[len] = '/'; + base[len+3] = '/'; + name = base + len + 1; + } + for (i = 0; i < 20; i++) { + static char hex[] = "0123456789abcdef"; + unsigned int val = sha1[i]; + char *pos = name + i*2 + (i > 0); + *pos++ = hex[val >> 4]; + *pos = hex[val & 0xf]; + } + return base; +} + +int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size) +{ + unsigned char real_sha1[20]; + SHA_CTX c; + + SHA1_Init(&c); + SHA1_Update(&c, map, size); + SHA1_Final(real_sha1, &c); + return memcmp(sha1, real_sha1, 20) ? -1 : 0; +} + +void *map_sha1_file(const unsigned char *sha1, unsigned long *size) +{ + char *filename = sha1_file_name(sha1); + int fd = open(filename, O_RDONLY); + struct stat st; + void *map; + + if (fd < 0) { + perror(filename); + return NULL; + } + if (fstat(fd, &st) < 0) { + close(fd); + return NULL; + } + map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); + close(fd); + if (-1 == (int)(long)map) + return NULL; + *size = st.st_size; + return map; +} + +void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size) +{ + int ret, bytes; + z_stream stream; + char buffer[8192]; + char *buf; + + /* Get the data stream */ + memset(&stream, 0, sizeof(stream)); + stream.next_in = map; + stream.avail_in = mapsize; + stream.next_out = buffer; + stream.avail_out = sizeof(buffer); + + inflateInit(&stream); + ret = inflate(&stream, 0); + if (sscanf(buffer, "%10s %lu", type, size) != 2) + return NULL; + + bytes = strlen(buffer) + 1; + buf = malloc(*size); + if (!buf) + return NULL; + + memcpy(buf, buffer + bytes, stream.total_out - bytes); + bytes = stream.total_out - bytes; + if (bytes < *size && ret == Z_OK) { + stream.next_out = buf + bytes; + stream.avail_out = *size - bytes; + while (inflate(&stream, Z_FINISH) == Z_OK) + /* nothing */; + } + inflateEnd(&stream); + return buf; +} + +void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size) +{ + unsigned long mapsize; + void *map, *buf; + + map = map_sha1_file(sha1, &mapsize); + if (map) { + buf = unpack_sha1_file(map, mapsize, type, size); + munmap(map, mapsize); + return buf; + } + return NULL; +} + +int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1) +{ + int size; + char *compressed; + z_stream stream; + unsigned char sha1[20]; + SHA_CTX c; + + /* Set it up */ + memset(&stream, 0, sizeof(stream)); + deflateInit(&stream, Z_BEST_COMPRESSION); + size = deflateBound(&stream, len); + compressed = malloc(size); + + /* Compress it */ + stream.next_in = buf; + stream.avail_in = len; + stream.next_out = compressed; + stream.avail_out = size; + while (deflate(&stream, Z_FINISH) == Z_OK) + /* nothing */; + deflateEnd(&stream); + size = stream.total_out; + + /* Sha1.. */ + SHA1_Init(&c); + SHA1_Update(&c, compressed, size); + SHA1_Final(sha1, &c); + + if (write_sha1_buffer(sha1, compressed, size) < 0) + return -1; + if (returnsha1) + memcpy(returnsha1, sha1, 20); + return 0; +} + +static inline int collision_check(char *filename, void *buf, unsigned int size) +{ +#ifdef COLLISION_CHECK + void *map; + int fd = open(filename, O_RDONLY); + struct stat st; + int cmp; + + /* Unreadable object, or object went away? Strange. */ + if (fd < 0) + return -1; + + if (fstat(fd, &st) < 0 || size != st.st_size) + return -1; + + map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); + close(fd); + if (map == MAP_FAILED) + return -1; + cmp = memcmp(buf, map, size); + munmap(map, size); + if (cmp) + return -1; +#endif + return 0; +} + +int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size) +{ + char *filename = sha1_file_name(sha1); + int fd; + + fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666); + if (fd < 0) { + if (errno != EEXIST) + return -1; + if (collision_check(filename, buf, size)) + return error("SHA1 collision detected!" + " This is bad, bad, BAD!\a\n"); + return 0; + } + write(fd, buf, size); + close(fd); + return 0; +} diff --git a/usage.c b/usage.c new file mode 100644 index 00000000..e774d2ef --- /dev/null +++ b/usage.c @@ -0,0 +1,40 @@ +/* + * GIT - The information manager from hell + * + * Copyright (C) Linus Torvalds, 2005 + */ +#include +#include "cache.h" + +static void report(const char *prefix, const char *err, va_list params) +{ + fputs(prefix, stderr); + vfprintf(stderr, err, params); + fputs("\n", stderr); +} + +void usage(const char *err) +{ + fprintf(stderr, "usage: %s\n", err); + exit(1); +} + +void die(const char *err, ...) +{ + va_list params; + + va_start(params, err); + report("fatal: ", err, params); + va_end(params); + exit(1); +} + +int error(const char *err, ...) +{ + va_list params; + + va_start(params, err); + report("error: ", err, params); + va_end(params); + return -1; +}